The Witcher 2: Assassings of Kings
You probably already heard about it by now, this is one of the best RPGs in some time it seems. metacritic tells me most reviews liked it, and, even more important, RockPaperShotgun wrote a very favourable review that you should read by the way.
I extremely enyoed the first part of the series when I recently played its "Enhanced Edition" which resembles the patched game including additional missions and improved voice acting (the voice acting is acutally great).
The game is released retail, on Steam or gog.com. The latter being the most noteworthy. Normally reserved for reissues of old games they offer this new release without DRM and including all the box content.
They also offer the first game for merely 5$ which is an incredible deal for 40+hours of entertainment.