Quite possibly the best fantasy RPG ever made and, definitely, the only Dungeons & Dragons game to ever feature both a Brothel of Slaking Intellectual Lusts and hundreds of thousands of excellent words, Planescape: Torment is an absolutely amazing offering. A classic. Black Isle's magnum opus and something you cannot afford to miss.
Oh, and you can (and should) grab a boxed copy via this Planescape: Torment (PC) eBay auction. The game seems to be complete and in very good condition. Seller ships worldwide.