It absolutely depends on the person and the book.

I gave one of my best friends a beautifully illustrated copy of The Hobbit, because we're both big Tolkien fans and I know he re-reads The Hobbit every few years, and an illustrated copy is perfect for him and his daughter. If I know someone is interested in a particular topic, then a history book or biography could be a great gift. I gave my brother A Knight of the Seven Kingdoms by GRRM because I know he loved ASOIAF. Books take a time investment, so I'm only going to give someone a book that I'm very confident that they'll enjoy.