^ That's so thoughtful (and useful)!
I love presents that are a surprise. I wouldn't have it any other way. My interests are varied enough that I don't think I'm horrendously difficult to shop for, which helps.
The best is when they help me to discover something, like a new genre of books, or an old musical.
And I know it'll sound cheesy, but I really do appreciate the thought that goes into it. My friends gave me a fantasically horrible Voyager novel one year. I kept it and read it from time to time. Definitely not the best book, but they aren't Trek fans and I love that they picked it out for me. Everytime I see the book on my bookshelf, I'm reminded that I have friends who don't care that I'm a complete nerd, and that they made an effort to support my interests.
That sort of thing is more valuable than the actual material good, I believe.