We were all AD&D'ers, to a man. Oh, sure, some of us would occasionally play Traveller, or Top Secret, or Star Trek (from FASA, with that really crufty tactical system), but we'd always come back to D&D.
Then one day, somebody (I think it was Brad, but it could have been Brian) said he'd like to run D&D from the old books. Well, we all said sure!
We all rolled up characters (3d6, play it as it lays) and set off. While wandering across the open ground to get to the dungeon, a dragon flew overhead. Thinking quickly, Dave said not to move. We all stood stock still.
The dragon circled, looking, but we didn't move. It circled again. Finally, it landed. Dave told us not to do anything until he gave the word. Puzzled, the dragon came into our midst and smelled us, but we didn't move. It even knocked one of us down (sorry, I don't remember who) and still nothing. It sat down.
"Now!" Dave bellowed, and we all fell upon the dragon and killed it.
I don't know of any other time a party of first level characters met a dragon and killed it, but this will always be one of my happiest gaming memories.
And I salute the rule system that made it possible!
Dieter the Deathless, anger-fueled fighting machine.