I'm a fan too. I have read till The Order of The Phoenix. I enjoyed The Goblet of Fire very much. That's where I got to know who Dumbledore really is. The Movies don't give much justice to the story so I would recommend you read them first before watching the movies if you haven't and are thinking along those lines"The Hobbit" from J.R.R. Tolkien of courseand "The goblet of fire" from J.K. Rowling once again(I lost count), yes I read multiple books at the same time^^.