I'm interested in recruiting new players for a campaign in James Maliszewski's infamous megadungeon, Dwimmermount. This is a really cool megadungeon –– political factions, a history of 1000s of years, etc. etc. The game is largely based on exploration and discovery; there's a lot of setting lore, and one of the goals of the game is to discover more.
We use Labyrinth Lord Core, with some house rules (and some rules that are Dwimmermount-specific).