I'm in my second stint. I played from 1981 until 1986/87, then quit because:
1) My group went all rules lawyery.
2) I hated the Survival guides, as they enabled the above.
3) Munchkinism was rampant.
4) I despised the way published modules were being written, and that is where my group wanted to go.
5) I had far too many other things going on to find another group.
Looking back, the problem was more of an issue with my group than with the game, but i didn't like the way the game was headed either. So my D&D development was arrested at 1E Core + FF + MMII + D&Dg + 83 Greyhawk boxed set, and a handful of modules, with the Moldvay/Cook basic/expert sets and a few modules.
I piddled around with 1E gamma world in college, but never got around to playing. When I saw 2nd edition AD&D, I figured I'd never play again.
Fast forward to 1997, and a co-worker gets me into Magic: the Addiciton. Played that for a while, and he kept nagging me to join his D&D game (1E). I resisted until 1999, then joined. Been playing almost every other saturday since then.
In 2000, I started hanging about Eric's site. In early 2001, I bought the core 3.0 books. In late 2001, I fired up my own home brew, which ended with a wimper at the end of december 2004.
So, about 11 years of total play, in two parts. Completely skipped 1E+UA (until recently when I decided to use the spells and magic, and the unarmed combat sections for my new 1E game). Completely skipped 2E and 2.5E, though I would probably give either a try with the right group.