So, 5E. Bounded accuracy, a huge plus. I would argue that it's easily the most efficient edition in terms of yield vs complexity. I've read a lot of complaints about the move away from technical writing; I've read just as many posts stating what a pleasure it is to read this edition compared to others. And, without a lot of fanfare, the authors have done a rather elegant job of making the core rules optimization resistant.
Not optimization proof, however. 
Here's my first take on an optimized 5E party. Because our choices are rather more limited than in 4E's toolbox environment, it's simpler to just describe the party then explain my reasoning afterward:
1. Half-Elf Valor Bard
2. Half-Elf Valor Bard
3. Half-Elf Valor Bard
4. Half-Elf Valor Bard
No, just kidding. (A little. That's a pretty solid party right there.) For reals:
1. Wood Elf Battle-Master Fighter with Protection Fighting Style. Dexterity primary with rapier and shield.
2. Human Thief Rogue with Sentinel (!) feat and Wisdom as secondary and eventually taking one level of Monk as soon as the party comes across its first Bracers of Defense +3.
3. Human Transmutation Wizard starting out with one level of Knowledge Cleric. Dexterity 14.
4. Half-Elf Valor Bard.
Here's what we can do with this:
* The Fighter and Rogue always work as a pair because this auto-enables Sneak Attack and Protection overlaps with Sentinel. The first enemy to attack the Rogue takes disadvantage from Protection. The first enemy to instead attack the Fighter (or try to sneak off to attack the Wizard) eats an extra Sneak Attack.
* On his own turn, the Fighter uses Commander's Strike to replace one of his attacks with a supercharged Sneak Attack assuming the Rogue has not already used his reaction with Sentinel.
* Meanwhile, the breastplate-and-shield--clad Wizard does his thing with quite a bit of durability. That thing admittedly is a bit less than a Warlock can do re DPR, but he more than makes up for it in sheer flexibility. Said flexibility includes the Rope Trick spell, essential for taking short rests (recharging the Fighter's superiority dice, his own spell levels, etc).
* The Bard is the ultimate utility player. Melee with rapier and shield, no problem. Back-stop the Wizard casting save or sucks? He's your guy. The Rogue feeling a little puny because of the heat that Sentinel is bringing down on him before he dips a level of Monk and his Bracers with Unarmored Defense couple with Uncanny Dodge to make him pretty stout? Yea, he's got that too.
* Skills? Everyone can afford Stealth and either Perception or Investigation. The Rogue can own every Dexterity and Wisdom role. The Bard of course has Charisma covered. With his two extra Knowledge domain skills, the Wizard can cover Intelligence. The Fighter has Know Your Enemy. (There's a mammoth RPG.net thread complaining about the lack of noncombat roles for the 5E fighter. I'm like, what? Creative use of Know Your Enemy would be absolutely huge in a lot of campaigns.) Only Athletics isn't covered by anyone's primary stat -- and admittedly that's this party's Achille's heel when some big uglies start throwing Strength saves at them -- but this group will be able to fly or polymorph through most terrain challenges.
* In the meantime, did I mention Stealth? The Wizard will be the worst at it, at proficiency+2, which isn't too terrible. Everyone also will have healthy Initiative rolls.
So, that's my concept of a well-rounded 5E party, at least until we see more of the game system. As always, discussion welcome.
Rancid_Rogue wrote:
mellored wrote:
I don't seem to be able to edit the original post to reflect the correction. Is there a trick to it?
EDIT: OK, I see. No more underlines or strike-throughs. I miss my "living document" abilities ...
Ah, the transmuter...where polymorph is free. I remember being given the 3.0 PHB many years ago, and, some days after reading it, asked by the DM 'what did I want to play?'. I had read the polymorph spells. "Transmuter" was out of my mouth before he finished (gray elf, eventually, I believe). And lo, I see that's still a thing. Excellent.
I thought the rogue could only sneak attack once per turn?
Litania84it wrote:
mellored wrote:
Litania84it wrote: