A couple of mega-adventures not mentioned that i like, but have not run to completion, is Tomb of Abysthor and The Grey Citadel.
My opinion of R(appan) A(thuk), it is awesome! Don't let the bad opinions scare you. If there is actually something you don't like in the module do what the previous nay sayers forgot to do, change it to your liking! No roleplaying? That was because your DM failed to integrate those elements of the module. There are plenty of opportunities in there for you to take advantage of.
RA is a thinking DM's module, it doesn't hold your hand every step of the way. That is part of its "1st Edition Feel".
Necropolis is awesome too. It is a case of where the DM will probably want to make a lot of changes, especially on those traps previously mentioned. If you want an Egyptian type game this is it.
A trilogy of modules that is good, if you can get past the editing blunders, is the Loch-Durnan series. A very solid story line with good background to draw on and develop. The first module is the only one they messed up badly on. The info is there, just not where they tell you it is, so you have to find it. Then make appropriate annotations for actually running it.
Definitely check out the Grey Citadel and The Lost Tomb of Abysthor, both by Necromancer. Very few Necromancer products are less than very good quality. I think the Grey Citadel should be put up for an ENNIE award.