Yes, the other forum would be best, but if you are still looking, my three favorite off-line RPGs of all time (all availbile on either X-Box or PC) are Star Wars: Knights of the Old Republic, Deus Ex 2: Invisible War (Very... "Different" RPG), and of course, you can't forget the mother of all off-line RPGs, THE ELDER SCROLLS III SERIES!!!
IF I had to choose, the best of those for the PC would be TES 3: Morrowind (and the two expansions), but the otehr two are great... though they do seem to be made for the X-Box....