You've really shortened the list of possible games that fit your categories, you know...
First of all, Jeff Vogel's rpgs are very traditional, party-based dungeon runs, and you oughta try at aleast his Avernum series. Here: http://www.spidweb.com/
Then there's Arcanum, a game which will be lauded be quite a lot of people on this fora, so I don't have to...