I don't know Rappan Athuk, but I have to give some praise for Castle Whiterock. Normally, I'm not a fan of megadungeons but this one is really excellent and most importantly for this kind of thing: It's well organized!I'd say that both Goodman Games' Castle Whiterock and Rappan Athuk 1-3 (or reloaded) are superior large dungeons to WLD, though Whiterock is much less well known, and I suspect fewer have played RA than WLD.
Hello out there,
I play Pathfinder, so I'm vaguely aware of what might (and I stress might) be considered the new classic adventures for Pathfinder. 'Stolen Land', perhaps? 'Burnt Offerings' (which, of course, was actually a 3.5 mod...)?
For me the one adventure that I can honestly say may deserve "classic" status are Age Of Worms Part One - THE WHISPERING CAIRN. Holy Crap was that a good module to run (and for my players at the time) a good one to play in.
I would also nominate a few of the Necromancer Games mods - Tomb of Abysthor and Crucible of Freya to that list.
From WOTC Red Hand of Doom and The Sunless Citadel.
Mind you, I'm not sure any of the Pathfinder APs, other than perhaps Kingmaker 1: Stolen Land, also have the shared experience element to rate as a true classic, either.
That will change next June when Burnt Offerings is re-released as part of the RotRL hardcover complilation. Then I think its classic status will be assured.