I have the original Masks of Nyarlathotep, the boxed set. Tons of handouts, including the famous matchbox, plus a world-spanning adventure. Very cool stuff, with some really creepy moments. Not fantasy in the heroic or swords & sorcery mode, though.
The Broken Covenant of Calebais, for Ars Magica, is very good. They touted it as a dungeon crawl that made sense, and it was exactly that. A new version of it was just released. I haven't read it, but if it's anywhere near as good as the original, it's a very good adventure.
I always liked Pendragon's modules. Most of them are actually compilations of shorter adventures. The ones I like best are the Spectre King and Blood and Lust. Each has several Arthurian-themed knightly adventures, but the one that stands out above them all is The Heart Blade, in Blood and Lust. The PC knight tries to woo a very worthy lady. Sounds lame, but Pendragon adventures often presented very tough scenarios that necessitated a lot of roleplaying and tough moral choices. This was the best of them, I feel. The Heart Blade itself is a potent weapon the knight can be bestowed with if he wins the lady, and its powers are based on love; in Pendragon, emotions carry definite game effects. There was another module, The Grey Knight, which I liked for Pendragon, which was a stand-alone. The knight PCs must help Sir Gawaine defend Arthur's honor in battle with an unkillable knight. Atmospheric and tense.
I also like many of the old MERP adventures and sourcebooks. Gorgoroth is my favorite, and details a part of Mordor that only really, really tough PCs will be able to brave. Dunland and the Southern Misty Mountains is a sourcebook I enjoyed, but which had some really un-Tolkien-like elements, like a flying elven castle and an elf doing bizarre Frankenstein-like experiments. The Fortresses and Cities of Middle Earth books are all very good, and, as mentioned, the maps (and the interior descriptions) can be used for just about any fantasy game with little alteration.