One of my all time favourites is Wizardry 8. Just about every thing in the game was well done.
Also love Morrowind with the expansions, but haven't touched in a while so will have to go back to it eventually.
Diablo 2
I was hooked on it for ages, and never even played it online. Eventually grew tired of as my character approched level 50. Will never play it again.
NWN
I liked it in the beginning but eventually it wained on me. Never finished it. Never will.
Divine Divinity
One of the few games to hold me to the end. I never generally never replay a game so I haven't beat it more than once.
PS:T
Great story and interesting characters. I never finished it though. Got bored eventually.
TOEE
Playing this at the moment and though I generally dislike the new rules of D&D based games I find the combat in this game excellent. The best tactical combat engine I've seen lately.
Icewind dales and Baldurs gates
BGs great RPGs, IDs good hack n' slash...over all I never finished any of them. Got bored.
Beyond Divinity
It's a game I will finish...it's got enough of the DD in it to keep my interest. Wish it was faster though. Characters seem to run in slow-mo! Dislike the skill system. Well into act 3 now and I've never had to use a skill in combat with a right click. No point in even buying most of them.