Wizardry 8?
Everyone says it's what other traditional CRPG, starting with Daggerfall, Might and Magic, etc. etc. should have been. Very non-linear, and almost bug-free.
I myself am three hours into the game so I cannot say much (like it so far tho). But it is all 3-D and sure can test your hardware if you turn all graphics options on and go for a high res
