Queen of the Spiders - 1st Edition AD&D
It's almost cheating to include Queen of the Spiders on this list. It's a "supermodule" that includes seven modules. It's more of a campaign, really. Players began by dealing with giant raids, move into the icy north and take on yetis and frost giants, and then delve into a volcanic land where fire giants abound. After that, they enter the Underdark and spend the rest of the campaign dealing with the evil drow elves, and finally their goddess, Lolth, Queen of Spiders. It's a long, rewarding journey through some of the best material TSR ever produced.