I only read the first two Percy Jackson books and I disagree. They are funny and entertaining, and Riordan does a great job of capturing the voice of a 12 year old (or however old he was). But the plotting was nowhere close to Harry Potter. The books had a bunch of loosely related side adventures, and could have made a decent TV show.
I am the Cheese! I am the best character on the show! I am better than both the salami and the bologna
COMBINED!