Holmes ('79~'82): I got this edition for Christmas, but the rules were mostly beyond my understanding. Didn't help when I lost the rulebook and only had B2 to reference. Also, since dice weren't allowed at school, we entirely narrated our games. Many plots were stolen from TV shows, movies, video games and the like, with D&D terms thrown in here and there.
Moldvay ('82-'84): A friend let me borrow his copy and I read the rules from cover to cover and actually started using them. The next year I bought about 20 modules off a friend and discovered that there was an Advanced version of the game. Sometime in '83 I picked up a flea market copy of the Moldvay books, Basic & Expert.
AD&D ('84-'89): As an 8th grade birthday present, I got myself the revised cover PHB & DMG (but not the MM - the DMG had abbreviated monster stats in it). As I transitioned to high school, I began to play more structured AD&D and over the years picked up more and more books until I had a pretty complete collection of the hardcovers and most of the modules. One significant note: If Dragonlance ('84) hadn't come out and absolutely captured my imagination, I probably would have dropped D&D in this timeframe.
2E ('89-'98): I picked up 2E as soon as it came out, took me about a month to consume the new rules. We were in the middle of a campaign at the time ("Link & Co."), and switched over to the new rules and finished that campaign out around '92 or so. I met my future wife in '93 and started a new group, we played until around '98 by which I had tired of 2E's quirks and was mostly playing Vampire. I still kept up with collecting D&D and had a subscription to Dragon, though. Oddly enough, I got an adventure published in Dungeon in #78, Jan/Feb 2000, just a little bit before 3E came out.
3E (2000-'09): I picked this up as soon as it was released and was playing once all the core books were out, and loved it. I was not enamored with the switch to 3.5, and stuck with 3.0 for about a year before switching.
4E ('08 ): Rubbed me the wrong way. Ran my group through Keep of the Shadowfell, and declared I wasn't going to DM for 4E any more. I played for about another three months with my group (as a player, something I hadn't done in 20-something years) before we dropped it for Pathfinder and several other RPGs I did (and still do) rotate between.
5E ('14): Started with the basic boxed set, and was instantly hooked. Been playing 5E ever since (though I've been slacking off buying "official" products for more and more 3PP since Tasha's)