It might be 11 years old but this is still one of the best games ever made. Sadly due to licensing problems it was only released for a few years and never seen again despite a huge demand for it...until now! $9.99 at gog.com http://www.gog.com/en/gamecard/planescape_torment
Cool, I recently picked up copies of the Baldur's Gate and Icewind Dale series but this was the critical standout from that engine and generation of D&D games.
In Europe it was actually re-released, and new copies on DVD are still available on amazon.de and .co.uk. It's more expensive than the download, but people who prefer a physical copy could order one.