I'll play and run in any D&D game other than 4E.
As a writer, I'm pretty bummed by 4E. I object to any game that dares tell me, the DM, not to place an encounter near a cliff that's too high for low level characters in the event they should fall off, or to not put a instantly deadly trap in my dungeons. I won't even write any material for 4E. I prefer challenge in my games, and a bit more escapism than what 4E provides. Plus, what they did to Paladins and Wizards was completely unacceptable. Just not for me. (BTW, for you 4E devotees out there, yes, I've played AND ran a 4E game: Keep on the Shadowfell. So don't tell me that I didn't play this game and don't get it. I do get it; it's just a terrible RPG.)
I prefer to run and play 3.x mainly for the sheer amount of options available for both a DM and a Player that are available, though I will run a 2E or 1E game.