c1981 - Get Moldvay Basic set, later Cook/Marsh Expert set, mess around for this for a while, primarily focusing on the Keep on the Borderlands and some half-ass homebrews.
c1983 - Get Advanced Books, for the next couple of years try very hard to make AD&D work for my group.
c1986 - Become interested in the Mentzer boxed sets, and more importantly, the Gazetteers. Go back to basic/expert style D&D for several years, starting again with the Keep on the Borderlands.Continue to play AD&D in Jim's killer campaign. In retrospect, I can't help but wonder if it was the original Unearthed Arcana that drove me back to the simpler rules of Basic/Expert.
c1989 - 2nd edition AD&D comes out. My group drops most of our BECMI gaming in favor of playing the crap out of 2nd edition. David Dalley runs his Krynn campaign, one of the best campaigns I've ever had the priviledge to play in.
c1993 - Running the Rules Cyclopedia, once again relying on the Keep on the Borderlands and the Gazetteers.
c1994 - Don McKinney runs a super campaign using the RC, with the highlight being a partial run of Night's Dark Terror.
c1996 - Run a superfun hybrid 1e/2e AD&D game set in the Bandit Kingdoms.
c2001 - After a lull 3e draws me back into DMing. Run a short campaign based on Quasqueton and the Caves of Chaos, set in "Greymoor", the World of Greyhawk version of Blackmoor. Somwhere around this time I started getting really into OD&D.
c2002 - Back to AD&D 1st edition for a short but entertaining high level campaign that ends with a party armed with Hammers of Thunderbolts pretty much destroying the Glacial Rift of the Frost Giant Jarl.
c2006 - I hop on board the 3.5 bandwagon with the Wild Times campaign, the best campaign I've run since the Bandit Kingdoms and the '80s Gazetteer game. Heck, maybe better than those. Have some good times in the World of Alidor. Run OD&D as a con game, which was a hoot.
c2007 - Run Moldvay Basic as a con game for ten players, the most I've ever managed at a single session. Good times.
Putting together this timeline was a fun exercise of the ol' noodle. I've omitted a lot of brief experiments and flubbed games and I've probably flubbed at least a few dates. Hopefully I haven't forgotten to mention any totally rad campaigns.
If anybody else tries putting together a similar timeline please let me know.