People I like will get access to Uncle Triumph's Item Farm. I'll go ahead and let everyone know, I'm going to be the psycho nutcase who plays the game for 12+ hours a day and min/maxes as much as possible.
From getting each class to at least level 10 in the demo, this is what I took away from it:
Demon Hunter- fun class. Fast as balls. Iffen you like shootin' shit, this is your choice.
Monk- really versatile, lots of cool aoe attacks and shit like that. You can totally use weapons too, don't be put off by "oh noes I haz to punch things".
Wizard- I had the most fun playing as this, although I think in the first five or so levels you're liable to have to actually watch your ass as opposed to the other classes. Once you start to unlock good skills n spells n shit you'll be hollerin' TEN POINTS FOR GRYFFINDOR, BITCH! at your screen as you asplode everything in your way.
Barbarian- Awesomely fun. Watching shit fly everywhere as you wallop the fuck out of it is really viscerally satisfying. Only caveat is that he's slow as fuck, so if you're playing with a bunch of ranged people enemies can be dead before you get to them, which will turn you into a sad panda.
Witch Doctor- not my cup of tea. Buffs, debuffs, summons, shit like that. I've heard that later on in the game this is one of the more OP classes, but I doubt I'll play it tbh.
I plan on starting a monk to tend my farm, but I imagine I'll play a Wizard and Demon Hunter a bunch too. Might eventually solo as a Barbarian to smash shit. Can't fucking wait for this game.