My vote is for 3.x, but I am even more specific to 3.0. With it I can crush my enemies, see them driven before me and hear the lamentations of their women. I also see my castaway self playing it with Ginger and Mary Ann.
The Fourth Edition brought me back to D&D. I left AD&D for Pendragon and Call of Cthulhu (and experimented lengthily with Runequest, Warhammer, Rolemaster and Powers & Perils).
I voted 3.xE. It the system that I've been playing for about 8 years now. So far we've managed to bend it a reasonable way without completely breaking it.
If 3 is lumped together with 3.5 and 4 is lumped together with Essentials, then shouldn't B/X be lumped together with BECMI and AD&D 1e be lumped together with AD&D 2e?
1st edition Ad&d still rules. Oriental Adventures and Dragonlance are still favorites to play. As well as 1st edition Forgotten Realms. My best loved character is from Dragonlance a Gully Dwarf Barbarian with poison tipped darts with blowpipe and a spear. His only armour was a pot that he wore on his head. Used it for cooking and latrine. The good old days of yore.
Although I have liked all editions thus far, I have to say, by the "good times" meter, that AD&D 2nd Edition wins out, with BECMI/RC as a close second.
If 3 is lumped together with 3.5 and 4 is lumped together with Essentials, then shouldn't B/X be lumped together with BECMI and AD&D 1e be lumped together with AD&D 2e?