I just picked this up the other day and all I have to say is... wow! If you like action RPG's and a dark mature storyline, this game is right up your alley. You play Geralt, a witcher who has lost his memory. I'm not very far into it, but what I've played is great. The enhanced edition is apparently vastly improved from the original release, so if that's the one you want. Though if you can't find it and only the original, they offer the enhanced update from their site free of charge. Enhanced edition also came with a short story of the game that seems to take place before the start of the game, very good read I might add.
Wow that looks fantastic. Too bad my computer probably can't run it, it could only run Oblivion on the lowest settings.