I'd have to rate the books as following:
3: I thought JKR did a great job of explaining some of the background of Harry'd parents. Also, Sirius Black is awesome and is introduced here.
4: Tri-Wizard tournament + Quidditch World cup and a ton of interesting plot twists (I wasn't expecting the whole Mad-Eye fake thing) really made this book great.
5: I have to say, this was probably one of the most infuriating books I read, what with Umbridge and the Order and Sirius getting OHKO'd, well it gave me plenty to think about.
7: Say what you want about the ending, I thought the last book was excellent, closed most of the loose ends, and was a good change from another year at school.
1: Where it all started. In hindsight, it seems really short and bland, which can be accounted to JKR still thinking up the whole universe. Still, this was the book that got me hooked.
2=6: Last place is a tie between books 2 and 6. Neither was really good or bad, but both were lacking. 2 felt like filler, with Voldemort's past self attacking instead of furthering the current situation. 6 seemed to be more of a pre-Hallows book, as it had so many cliffhangers and questions, didn't feel like a complete book.
As for the movies, I haven't liked any of them really, with the exception of #3. Even though it deviated substantially, I felt they pulled it off remarkably well.