Dragon Age: Origins - a masterpiece from Bioware, which I consider one of the best PC games of all time.
The most I liked about it, that it wasn't too long to go through, the length was almost perfect for me, played it twice already, and sure would return back in the next few years.
Mass Effect 1 another great game, but what holding me to replay is the planets discovering thing, mostly waste of time with a few bases that you could find.
Based on multiple recommendations for Kingdoms of Amalur: Reckoning, now it's in my whish list and definitely I would visit some day, thank you guys.
Btw, I just finished The Witcher 1 in ~60 hours, a wonderful gameplay, characters and story. The combat system kept me engaged and never bored of it, I finished it in normal difficulty.
It went to the list of best PC games I ever played, and very nice graphics / world for a 2007 game.