In all MMOs I'm typically some sort of caster class before anything else, but, I liked my Assassin more than anything, even if I did build it REALLY badly because it was my first char.
I generally don't play as the 'tank' classes because that's just no fun. You stand there, and you click and hold and that's pretty much all you do. Occasionally, you BA or something. Woohoo. Warrior type classes have to be the most boring ever.

I enjoy the GFX style of Diablo more than most games because it's not about looking flashy and distracting the simple minded with shiny big swords of death. It's more about the game play, but you're right on with the imbalance. Typically though, that's the way it is. The Mage classes are usually the most damage dealing.

And for the community. Well. Any MMO is going to be like that. It's just a shame that because D2 is getting on in years that a lot of the decent people stopped playing, and their spaces have been filled with the type of people that come in to PVP games with level 1 characters just to loot.