(Start from most recent one)
Fallout: New Vegas - Hell yeah, I've spent more then 50 hours on it and there are more to come. Multiple endings for ze win. (59 hours)
ArcaniA: Gothic 4 - Utter disappointment, the gameplay was ok but the atmosphere and story (pretty much the most important parts of a RPG in my opinion) just plain sucked, geting Gothic 3 alongside it for free made it.. almost worth it. (Gothic 3: 22 hours, Gothic 4: 6 hours)
Civilization 5 - Twas worth it, good addictive fun for a couple of weeks, kind-of stoped playing it now but I'm looking to give it another go and maybe start a multiplayer campaign with a buddy of mine. (40 hours)
50 or so euro per game.