http://www.pcgamer.com/2012/04/02/l...gog-this-thursday-courtesy-of-cd-projekt-red/ First thing that comes to mind is Baldurs Gate. Or maybe original Witcher. Or perhaps the Witcher 1 redone in the Red Engine PS. Cd Projekt are really the best Devs out there now.
Baldur's Gate is already on GoG, so is The Witcher. I'm guessing Wasteland frankly, what with the recent Wasteland 2 kickstarter. EDIT: Oh, a game available for free that's already on the catalog.