Voted 3.5 even though I play only Iron Heroes and d20 modern/akopalypse atm.
I am however a faithfull believer of the D&D 3.5 system and it's adaptability and have played it continually since it came out (mostly Eberron). I'll almost only DM adjusted D&D 3.5 after my Iron Heroes campaign.
Running a 3.0 game. 3.5 came out during the middle of my prior campaign and we waited till that was over to make a decision about changing to 3.5. I put it to my players and they wanted to stay with 3 rather than 3.5.