I really hope they incorperate string instruments in later titles. What are your thoughts on that? Do you have any prefered sounds for fantasy games? Or do you use a different custom soundtrack while playing? If you do, what kind of music do you listen to? Have any classical "adventure" tunes to suggest?

Well, this person has a Soundtrack played on Piano if the next game were to be in Valenwood or Elsweyr

http://www.youtube.com/watch?v=VRont0vPzfM

I would want them to use instruments that fit in with the theme and style of the game-world. Something that helps immerse you in the world.

Skyrim's soundtrack did a perfect job of that, but obviously that wouldn't fit in with all the provinces of Tamriel.

I never listen to other music when playing games because it can, and does, break immersion. Immersion is a huge factor for me when playing games, reading a book, or getting into any form of fiction, really. The audio (music, sound effects, and voice acting) is a very important parts of the game, and the experience the game in trying to acheive.