within the past years:

1. Baldurs gate 2 (with TOB)
2. Baldurs gate 1 (with TOSC)
these 2 have the best story line of any. not to mention getting it one with the ladies.

3. Planescape:Torment
4. Warcraft (2?) I don't remember which one. great MP game.

second tier: Fallout 2, Quake 2, IWD, IWD2, Neverwinter nights (but this is meant as a game creation tool not an adventure although they include one). Starcraft

Ive played other stuff, they arent memorable though. right now i am in the middle of NWN to pass time. gettin board though.