Couple of fun things I worked out, that I forgot to put here.
But since I referenced them in the Monk thread, I should point them out.
Deep Gnome Wizard: Abjurer. Stats 15,14,13,12,10,8. Giving you 17 int, 14 dex and con, 12 wis and you pick whether to dump str or cha.
At level 4, take the feat Svirfneblin Magic. At level 8 take observant, and at level 12 take +2 int
So you have the guy with huge passive perception, and temporary HP.
This is a wizard with fighter level HP, who can use their at-will Nondetection to refill the Temp HP supply between every fight.
Additionally can use their reaction to have their ablative HP used as preventative damage reduction on allies.
Using average HP this guy, at level 14, has 86 HP and 33 ablative HP (so effectively 119HP with lots of bonus healing)
A fighter of the same level has 88hp + 14x con bonus. So at con 14 (human w/ 3 feats) you get 116 hp, at con 16, you get 130, and at con 18, you get 144.
This means that the gnome in question has comparable HP to the fighter.
Secondly, the strength dump Barbarian, or the "I am played by Orlando Bloom in the movie" build.
Variant human, 15 (becomes 16) in each of dex and con. 8 in str. other stats as you see fit (say wis and cha 12 and int 10)
Human feat. either 2 weapon fighting for a bit of extra damage, or sentinel for extra stickiness.
Totem Barbarian, either Bear/Eagle/Bear (if you expect lots of magic damage in the campaign) or Wolf/Eagle/Bear (if there are multiple other melee in the party)
Your weapon of choice is the Rapier, paired if you went TWF, or with a shield otherwise.
This starts you with an AC of 18 at level 1, and by using your levelling stats on dex and con, you can end up with an AC of 21 by level 14, more, with a magic shield. (1 les AC in the TWF build)
You also end up with 159 hp (if you maxed dex out first) or 173 HP (if you maxed out con first) and half damage from some things while raging.
You lose the bonus rage damage.... at first.
You see, part of this trick is triggering the DM's twitch reaction. Many DM's will see Barbarians as played by Arnold Schwartzenegger, not Orlando Bloom. So you are very likely going to see far more gauntlets of Ogre might, or belts of Strength in loot than pure random chance would indicate. Best of all, if such an item does drop, you get more benefit out of it than any other melee, so it is more likely to go to you.
These two builds are each fun on their own, but get nice synergy if played together.
You have a sticky as hell, rapier and shield rager. Then you got the arcane caster adding even more HP to the rager, saving healing hit dice and ensuring a much longer survival time.