Song of the Fens remains my very favorite D&D adventure. It's in Dungeon Magazine #40. I've said so before in these threads but it's worth repeating. It's got a noble knight errant, a damsel in distress, an inn everyone hangs out in, a spooky monster in the swamp, rumors to be collected through social interactions, and a wilderness area to be explored for monsters and treasures, and a little lore to uncover.

I think it is the single best first adventure for new players, hand down, ever. It's pretty on-the-rails so no one is ever confused about what they should do. The story is just goofy enough that people feeling self-conscious about roleplaying have something to break the tension. And it's got every single element you expected, when you thought about "What D&D must be like," before you ever sat down at the table.