Well....Books are obviously more detailed and you get more detail as well as more of the "little things" in hogwarts life (Quidditch, classes, their everyday life etc) so you get more feel.
Movies have cool effects and you get a visual perspective and...it all looks epic. I really cant tell which one i like more as i am a huge HP fan and i love both but...Books have PEEVES xD
its a tie for me.
My favourite characters'd be Grindelwald, Moody, Sirius and Albus, though i dont particularly dislike anyone, all the characters were unique and awesome imo