Mannheim Steamroller has several that I like.
I am listening to Steamroller and realize that there are a few vocal tunes. They blend so well into the "orchestra" that as background music you are likely not to notice it.
Anything Windham Hill will be a good choice, as Mal said. Winston can be found there, but he may have his own distributor now. He was GREAT when we saw him Texas. (Walks on stage in his socks; gotta love that says the barefoot girl)
