What books or series are like Harry Potter?

Question:

What books or series are like Harry Potter?

I love the Potter series, but I'd really like to find more books to read as there are only so many Harry Potter books. Does anybody know of any books or series that are similar in topic or that are just really good to read if you like books like Potter? I'm a college student (I know, I'm embarrassed to admit that I'm a Potter fan since they're kids books) so I'd prefer something a little bit more teen/adult rather than something you'd find in the Juvenile section.

Best Answer - Chosen by Asker: The Chronicles of Narnia come to mind.