3.5
But its going to be difficult to convince my players to buy the new rulebooks. I like the changes and I like the clarity of the rules (esp. combat).
In any case, the 3.5 corebooks are going to be the last RPG books I'll buy for a long while now. As I've said before, gaming books are too expensive for my taste--I got the 3.5 books off amazon for 30% off. That was really the only way I'd have bought those books. 3.0 worked well enough to play a game. I wasn't going to pay full price just to get clarified rules and SOME new artwork.
Well, there's my two cents.