GW1 is Gamma World 1, yes.

i really like gamma world and will be giving that some game time soon methinks (after GenCon)

Al

I'm voting for a tie between B2 and the DMG.  B2 was the first adventure I ever went through, way back in 1980, and I'll never forget how it hooked me on D&D for life.  The DMG has been the most referred to and the most admired by me over the years.

S1 Tomb of Horrors comes in a very close second.  A sentimental favorite that introduced me to the term "total party kill".  

Not to be repetitive, but I just have to throw my own vote for Keep on the Borderlands.  Like countless other gamers, this was the first published mod I ever owned or played.  To this day, picking it up and thumbing through it gives me that warm glow.  Such good memories!  Ahhhh, those were the days...  

If Gary hadn't written anything else, this would have been enough.

I feel like there's an echo in here, but I'm gonna have to go with a toss-up between B2 and the 1st ed DMG.

B2 was, like so many others here have said, my first exposure to playing D&D (I returned to town and beat the snot out of the rumour-monger in the tavern who dropped the hint about "Bree yark!" being Goblin for "We surrender!"...never again...*grumble* *gripe*).

But the DMG is what I'd sit and read through on days when I wasn't feeling well and could only lay in bed instead of going outside.  Once I had enough of the rules down that I felt I could be a halfway-competent DM, I started playing with friends and creating my own little adventures.

Both unforgetable.  Both impossible to beat.  And both worthy of the highest accolades, as far as I'm concerned.

Grug Greyskin wrote:I'll through in another vote for B-2.  What a great intro to DnD - Kobolds, Goblins, Hobgoblins, Orcs, Gnolls, Bugbears, an Ogre, an Owl Bear, a Minotaur, a Medusa and an Evil Undead Loving Cult.  Can you pack any more excitement into a low level module?

If only Drow had been invented.............