Is there a game, genre, setting, or character type that you will not play, at all? Is there a deal breaker game element (like the previously mentioned) that will make you consider walking away from the table if the DM was absolutely intent on playing it? (I am not talking about a DM/personal characteristic.)
Bullgrit
Before I post my response, let's all get one thing straight--I don't think there is any such thing as a "bad" or "stupid" game. If you play it and you like it, that's great. If your favorite game makes my list, don't dish out the crap on me that I don't like your favorite game that's given you all your happy childhood memories, saved your marriage, got you your big promotion, and has made your children the well-rounded upstanding citizens they are today. Good for you and I wish you the best of success (really!) so here's my list of games that I won't play:
1. Anything White Wolf. My own experience is that is that I played Vampire and Werewolf with goths who were more concerned being goths than gamers and it didn't jive well with me. I want Underworld, not a reminensce of a depressing state of being as a vampire/werewolf/whatever. Not a fan of the system either, but who knows, I may change my feelings on that.
2. 4e. Read it. Didn't like it. No interest.
3. Palladium stuff. I played TMNT and got tired that a simple battle took 3 hours to resolve.
4. Anything "anime-ish". I like some anime, but I'm not some Japanophile.
Genres:
I'll play just about any genre except the anime one. I'm more into PG-13 kind of games so I don't dig games that are into gratuitous sex or violence and I certainly don't roleplay that. I try to be the kind of player that people from all walks of life (within normality) can game with.
Characters:
I typically play just about any character but I like to define my own personality. If I run into a GM that wants to assert control of my character's development and personality, that's crossing the line with me. I won't give an example as that I think it's a violation of TOS here. I try to make my characters also individuals that players wouldn't find offensive. I don't create chaotic evil assassins if the campaign is going to be about heroics.