Of that D&D game generation, Planescape: Torment is by far the best. One of the few computerized RPGs where you have real options in how to play (i.e., you can actually play a charisma heavy smooth-talker and still achieve a legitimate ending) and have varying story trees so if you play multiple characters in divergent playthroughs you see different story branches.

I've played pretty much everything else listed (save IWD2), but this is your best bet.