We messed around with 3rd Edition in college and enjoyed it but we avoided 3.5 like the plague.
I read through 3rd edition and didn't care for how they gimped the rules. I like 2nd edition for the most part, using a fusion of some first edition rules. So in my main (really good) group, psionics were first edition, hand to hand was from 2nd edition Oriental Adventures (still the best PnP hand to hand system ever made), monks were also from Oriental Adventures, Psionicist class was first edition from an old Dragon magazine, Special sub-classes from Unearthed Arcana, and magic was a fusion of the two... example, fireball/lightning bolt were first addition while protection from fire/ice was 2nd... along with stoneskin and a majority of spells.
The world we used was a variation of the Forgotten Realms with some aspects of Greyhawk thrown in... along with the Cthulhu mythos from the first printing of Deities and Demigods (they were forced to remove Cthulhu & Melnibonian mythos in subsequent printings as they had no license to use them). Ravenloft was also added at one point near the end, but the group split up as we all moved away. Never found another group where all the players knew the rules like the back of their hands again... sad really.