Personally it was the six hour tic-tac-toe game with a magically imbued door that finally saw him so far in our debt that he was forced to open and lead us to the dungeon boss.
What are yours?
That my pcs did? My converted Key of Destiny where they slaughtered their way through the camp in the end of the starter adventure they give you in the Dragonlance Campaign Setting. (More minions than you could shake a stick at.. ((try around 15 minions, six to seven "standards") They had to retreat but they killed the minions and more than half of the standards. That was pretty awesome.
Maybe overcoming the Skull Skull encounter in Kobold Hall... that was pretty heroic in my opinion.
My online group there's quite a few more heroic moments. One of which involves a bottle of wine, a candlestick and a tight rope.
Paladin in heavy armor attempts to jump through a waterfall into the cave behind it. Fails horribly. My rogue, who had already made the jump, dives to grab him before he falls.
A series of skill checks prevented (what, looking back, I would not just call a skill challenge) the two of us from plummeting down a rather large waterfall, preventing them from going on to save Daggerdale.
The problem was, after I had grabbed him, we continued to fail checks to climb back up until the party's battle rager was able to get down to us and haul us back up.
The party loved how there wasn't a moment of hesitation.
They needed to sacrifice three elf virgins to do so.
They were surrounded by an army of orcs, trolls, and hill giants.
We were third level.
Luckily for the world, if not for the virgins, we all had bows...and it turns out that you can't sacrifice dead people.
I think my favorite moment came when we were trying to prevent some orc shamans from opening a gate to some horrifying winter realm.
They needed to sacrifice three elf virgins to do so.
They were surrounded by an army of orcs, trolls, and hill giants.
We were third level.
Luckily for the world, if not for the virgins, we all had bows...and it turns out that you can't sacrifice dead people.
Wow I was not expecting the story to go that route. I was expecting some sort of "so we wooed the virgins" ending.
Wow I was not expecting the story to go that route. I was expecting some sort of "so we wooed the virgins" ending.
Yeah it seems like de-virgining ;) them would have been better than killing them.
Well our party's barbarian figured he could. And after what was perhaps the greatest string of rolls I had ever seen he managed to strike an invisible bumble bee without the aid of magic from 10 ft away, killing my nefarious villain and throwing all of my plans for him into disarray.
I've told this story before - a group of five 2nd level characters (1st/2nd Ed. days) get stopped by about half a dozen orcs in a pass between two hills.
It was just supposed to be a shave-off-some-party-resources encounter designed to send then fleeing toward the town in the distance.
In the middle of the orcs shaking down the party for gold, the orc shaman makes an insulting remark about the party cleric's god.
S.O.P.(standard orcish procedure), right?
Unfortunately, the cleric is being played by a real life nun, who raises her staff, cries "Blaaaaaaaaasphemerssss!!!" at the top of her lungs, and proceeds to Kick Ass For The Lord, lol.
Three rounds to kill half a dozen orcs.
I sent in reinforcements.
All dead.
I sent in more reinforcements.
Rinse and repeat.
Through the most rediculous series of awesome dice rolls I have ever witnessed, five 2nd level charaters laid waste to nearly two dozen orcs, and they were barely scratched.
I wasn't just speechless, I was completely brainlocked.
One of my own...
My old-school 5th level thief is leading a troll into an ambush in a cave system.
The plan was to have it chase me until I duck around a corner and scale the wall to a high ledge to hide until it passed me.
I had to get behind the thing so I could come up and backstab it after it ran into the rest of my party in the second cave - you actually needed to be behind somebody to backstab back then.
Things were going great until it stopped dead right underneath me while I was hiding on the ledge over the entrance to the first cave, sniffing around like it knew I was there.
Off in the distance I can hear the sound of another troll approaching.
I figured I had about one round to do something impressive.
I reversed grip on the magic sword I'd borrowed from the fighter (to backstab the troll with), jumped off the ledge 10ft. down onto the troll's head, and...
Crit (x2 damage) with a +1 flametongue bastard sword
+
sneak attack by a 5th level thief (x5 weapon damage)
+
10 feet of falling damage
=
I just one-hitted a freakin troll...:D
Even better, I saved the party a whole lot of grief by taking out two more of the damn things using that same tactic.
(Neither of them single-shots, but they were still damn quick.)
But one character of mine had that thrilling moment of victory (even if it nearly ended in my typical tragic defeat). Nived Devril, 3.0 druid, this must have been around 2001 or so, yes my screen name comes from that character. He was 14th level when the campaign climaxed. A vicious army of assorted giants had swept over the land, Nived's home town had been burnt to the ground and those not slaughtered had been enslaved.
The last bastion of freedom was my partymate's hometown a dwarven hold in the mountains. We were there rallying an army... while the armies clashed we swept behind enemy lines and killed the giant generals in a bloody battle.
The giant armies were routed, we won. While we were planning on getting our just rewards from the high thane we learned this wasn't meant to be the capstone of the campaign. There was more, the high thane turned out to have been replaced by a red dragon (can't remember the age category). Were were all spent, we were all low on hp and spells.
When the red dragon revealed itself we were meant to retreat... pretty much everyone did... because they failed their saves against Dragonfear... everyone but Nived. So while the dwarf and the two elves were running the gnome stood his ground...
"You're not going to run?" said the DM.
I looked at my sheet. I had one high level spell left... I never got a chance to use it in the battle against the giants... good ol' 3.0 harm (it was on the druid spell list back then). No save, target reduced to 1d4+1 hp. All I had to do was beat the spell resistance. "This ends here, I cast harm." I rolled to hit his touch AC, nailed it, and rolled to beat the spell resistance... I remember the DM telling me I was going to need to roll over an 18... "Nat 20"
"Your unholy glowing hand touches the dragon and blood starts to poor from between every scale on his body" I distinctly remember the DM saying that... then the dragon attacked me for all it was worth. I somehow survived with something like 4 hp left.
At this point the party stopped running and the sorceress cast one of her last spells, a simple magic missile... she beat the SR... and killed the dragon.
Just like that we killed the entire last arc of the DM's campaign (I wasn't trying to do that... just sorta happened). As they pulled my tiny barely conscious form from under the bulk of the dragon I declared, "Okay, technically you killed it, but I think I get to take credit for this one."
Nived remains to this day my only character who retired happily. After defeating the dragon he lead his freed people to rebuilding his hometown, using his nature magic to repair the scorched earth, he became the town's greatest spiritual leader, and lived on the outskirts for the rest of his days.
Edit
Unfortunately, the cleric is being played by a real life nun, who raises her staff, cries "Blaaaaaaaaasphemerssss!!!" at the top of her lungs, and proceeds to Kick Ass For The Lord, lol.
Just goes to show you not to tick off nuns.
Towards the end of the EtCR campaign, the DM used Strahd early in the day and we forced him to retreat back to his coffin. We found out earlier where the Crypts were due to some dubious negotiations, and figured we'd at least take a look at the defenses. The DM then throws every single vampire in the castle at us in an attempt to force us into retreat. Two greater turnings later, every vampire in the castle was forced to make for their coffins. Leaving only one guardian left to defend Strahd. It was a tough one, and it did turn one our group into paste (the poor guy had three PCs killed in the campaign, the only party deaths!). So we gather around the coffin and open it up, the DM calls a will save for me, but as an Outsider the gaze had no effect, he calls a will save for the adjacent rogue, who was the epicenter of a magic circle vs. evil spell so no effect, then the warblade, who used an ability to turn it into a concentration check which he easily made. Out of targets, the DM could only sigh as we jammed a splintering piece of wood through Strahd's heart.
In Dungeon's Shackled City path, I managed to crush a BBEG beholder to death with a pipe organ and a Grand Piano towards the end of the 1st adventure using some 3.0 summon instrument cheese.
Good times... good times...
We were 4, Level 7-9 characters and we were finishing a dungeon and a quest if I recall it correctly. Well we meet up with the BBEG wich turned out to be a ogre mage, and engaged him in combat... in an open area. Well the ogre made itself invisible and flew over our heads almost killing the spellcasters in the group. It looked like a slow TPK .I was playing a cleric, almost out of spells, cast enlarge person on myself and roll an attack against the ogre. Critted,dispelled its invisbilty so the others in the group, with phenominal good rolls managed to kill it in the following round:D
Coming across a half-ogre and some goblins in a glade, the knight and the cavalier charge into battle, each eager to be the one to engage the half-ogre (they constantly tried to out-brave each other) and I turn towards the goblins. I fire my blunderbuss (it was cool, so the DM let me have it, along with a -3 on the attack roll) at the goblins, splatting two of them, the DM rules the others leg it spooked by the loud noise and the sudden demise of their fellows (which is lucky, I had a three-round reload on that badboy, and that was probably the only time I ever hit with it), while the two meatheads start trading blows with Mr Big and Ugly.
Realising that my spells are probably of zero use here I watch the half-ogre start to beat up my friends, and decide to draw my pick-axe and give it one in the back, cue high roll and a nice amount of damage. 'Ah,' I say. 'It's probably stuck there.' The DM agrees (I'm dreadful at giving DMs good ideas).
I spend a couple of rounds trying to jump up to reach the pick-axe, and the ogre knocks out my friends. The half-ogre turns round and looks at me, 'What are you going to do?' Asks the DM.
Thinking quickly, I grab the hammer out of my tool belt and state boldly 'I'll throw it at the ogre.' Yeah, a -3 on the roll again. 20! I roll a d3, get a 3 and the DM tells me that I've knocked it out, it falls backwards and the pick-axe skewers it. I cheer and start working on a plan to get my pick-axe out.
The DM describes how the woman the half-ogre was menacing comes around from her faint. 'What woman?' I ask.
It became a re-occurring feature of that character that in any description, speach or exposition I would only hear the parts that were of interest to the character, it wasn't even deliberate, I only had the slightest grasp of the plot and was continually getting into trouble by focusing on one feature and ignoring the dangerous stuff (while the knight and cavalier fought each other to get to the dangerous stuff).
I, the Ranger, went to a secluded tomb with a Fighter and Wizard. I am the first to enter the tomb and am hit by a vicious acid spray. Some healing later, we explore around. We found a sloping corridor going downstairs to a locked (and trapped) door. We also discover there is an entrance to the lower floor through a pit. As the sneakiest member, I was elected to check it out.
I fail my Climb check and fall!
I roll a great Stealth check and make no sound. :embarrass
I peek around the corner and see a beevy of goons. I also realize that, across the room, is a locked door much like the one we stopped at.
I came back up, told the party what I say, and formulated a plot: The Fighter and Wizard sneak down the pit, while I lead my horse to the door. I break (or open) the door, charge with my horse, while the other two attack from behind.
Everyone set up and was waiting for me. Unfortunately, my suspicion of a trap was confirmed when a wall slide in behind my horse and began closing in on us!
I bade my horse to kick down the door! One round, door up, walls closing! Two rounds, door still up, one round until the wall crush me! Third round: My horse scores a Nat 20 on the door, and smashes us free! The guards move over to launch bolts at me and my horse. I respond by trampling them with my horse!
The rest of the party joins in. After a few rounds, the BBEG emerges: a half undead, half-plant monstrosity. He drops the Wizard. We fight back. He drops the Fighter. I attack back. He kills my horse. That was the last straw!
On single-digit HP, I charged the undead with my scimitar, hit, and slew him a turn before he could do it to me. 
Kakumulani, aka the Cartographer, planeswalker extraordinaire happened to find an adventuring party in the usual manner. Falling out of the sky in front of them. He chatted with them, took a liking to the bunch, and decided to assist with their adventures.
The party had a stone. The big, bad, artifact of doom kind of stone. It granted wishes. Any wish. But after a certain number of wishes, it cracked open. And deep inside lurked one of the most ancient forces, part of the duality that created the universe, which would overbalance all reality and tear it asunder. Unfortunately, everyone wanted the stone.
After fleeing massive bandit raids and extraplanar invasion, monstrous marauders and demon invasions, the party were surrounded on all sides by extraplanar forces. Demons and devils, archons and eladrin, all intended to seize the stone, either to manipulate it or protect it for all time, yet the resulting battle would tear apart the region, and the outcome was anything but clear. Well, Aku couldn't have that. He had somewhere to be, in about 1273 years, to save a certain girl from an rift in time. But that's another tale. So he decided to risk giving the stone to the one being powerful enough to defend it and ambivalent enough to not give a damn about using it.
He gave it to the Lady of Pain.
Upon fleeing the invading forces through a dimensional rift, tearing his way through Sigil, navigating the Lady's castle, and placing it before her and requesting her aid, he was rewarded with a single nod from Her Serenity, and promptly got roaring drunk in Sigil's finest seedy tavern to celebrate.
The problem for us is that there are like 10 grunts (about 6th lvl) and 2 bosses. One is a troll blackguard and the other is a human fighter. I quaff a potion of invisibility (so does the bard) and we sneak in so i am in a sneak attack/flanking position on both the black guard and the troll, with the bard on one side of the fighter. On the queue of the bard singing the shifter is to charge the troll. So the bard sings, I crit the fighter in the surprise, then its the shifter who runs up and clubs the troll, i opportunist crit the troll, then crit 2 more times. I'm rolling 8d6 + 1d10 + 10 on my crit rolls, all 3 on the troll ended up getting at least 40 points. So before they get to act (go having a party roll high for initiative for a change!) we have seriously injured their leader and killed a lvl 12 blackguard troll.
This encounter was meant to have our 4 player party running to our boat (docked at harbour) and running away...but then the DM forgot how much damage i can put out in 1 round...hehehe...and since then all we've got is constructs, undead and things that for no reason climb up 5 feet (like spiders) just so I can't flank for my bonus 6d6...so not fair!
But then, I did completely F*ck up a recurring NPC that was going to be hunting us down...but thems the breaks
Man, the DM was ******...
Of course, he became a patron of adventurers in the area, so I guess it all worked out.
Edit
Just goes to show you not to tick off nuns.
I swear, that woman's inconcievable luck with dice during that game is the surest evidence of the existence of a Higher Power I have ever witnessed... geez. Honestly, she could've rolled a natural 20 on a d6.
We started referring to her "walking stick" (quarterstaff) as the "+5 vorpal ruler". :D
I can't remember if I missed or just didn't do that much damage because it was a swarm, but whatever the case my tactics were not effective. The rats proceeded to crawl all over poor Thokk, who then failed his save and started barfing his guts out due to how plain disgusting it is to have rats crawling all over you.
The cleric and the rogue however had a plan. The cleric took one of the flasks of lamp oil he was carrying and splashed it all over the rats, and therefore Thokk. The rogue then took his torch, which he had been using to light the way and set the rats (and Thokk!) alight. So now I'm watching in horror as my precious first ever character is sick, covered in rats and growing steadily more crispy.
Fortunately, Thokk could take more punishment than the swarm of rats, and they burned up (with a little help from the rest of the party chipping away at them) before I ran out of HP, when the cleric made up for priming me with a CLW or two.