Percy Jackson Series

I have been reading my son's Percy Jackson and the Olympians series books. I was pleasantly surprised to find them incredibly interesting, and difficult to put down. Just so I a clear, they are definitely targeted at teens and pre-teens as far as content and story go, but they are also a good read. Book 1, The Lightning Thief (also a major motion picture) is the best of the four I have read so far. The Sea of Monsters, The Titan's Curse, and The Labarynth are the next three in order also good, but begin to get a little predictable and repetitive, but still good reads. I am waiting for my son to finish the last one, so I can sink my teeth into it.