Not to pile on, what with the Steam Summer Sale still in full swing, but I just picked up the Dungeons & Dragons Anthology for $13.98 at Best Buy. I didn't even know it existed until I walked into the store.
I mention this not because it has the full Baldur's Gate series with expansion packs (it does), nor because it has the entire Icewind Dale series (it does), and definitely not because it has The Temple of Elemental Evil (it does, but who cares?) I don't even mention it because all of the above have been updated to run properly on XP/Vista/7 (they have).
I mention it because it includes Planescape: Torment, the most fascinating (and most obscure) RPG I've ever played.
If you have even a passing interest in RPGs or BioWare/Black Isle, I highly recommend grabbing this while you can. It would be a bargain at fifty clams, but they're selling it for a fistful of mussels.