Witcher Theme - electric guitar ver. from credits
 

http://lesnik018.wrzuta.pl/audio/cADaYx0bur/believe

How do you like it ?

I like it. It captures the feel of the game very well -- the beautiful, wistful, melancholic surface, with the aggression and anger lurking beneath. Musically this is better than the Celtic-instrument rendition in the game, but I'm glad they reserved it for the credits -- there is such a thing as too much of a good thing, and I'm sure that around hour 20 this would have started to grate.

Here's another interpretion of Witcher theme by Tothaje. I found it on youtube - this time with vocals.

http://pl.youtube.com/watch?v=GO6-kT2Y2KY

enjoy :)

EDIT:
And maybe you'll be interestted also with music from the Witcher film (yes we did it, but nothing to be proud of ;) ). But the soundtrack was one of few things liked about it.
http://pl.youtube.com/watch?v=ce1MC48T3p8
http://pl.youtube.com/watch?v=14hMpbIqCk0&NR=1