Just finished the entire game in 80 hours (including The Descent and Trespasser). My first time playing it also. I thoroughly enjoyed it and thought the atmosphere, music, characters and story were excellently done.
Sadly it left me wanting to play it again. But alas, that is what makes it a great game. The fact that at the end, I didn't want it to come to a close and now that it has, it is time to play it again.
I have never played a Dragon Age game before, and this was a wonderful introduction to the universe.