I've read every book in this series (except of course The Last Olympian because it's not out yet). I thought they were great! I love the twists they put on Greek mythology, like Circe (godess of magic) deciding to turn men into guinea pigs instead of real pigs like she used to. I often find Percy hard to relate to, so I just try to focus on other characters like Annabeth, Grover, and Rachel. Rachel is awesome! She's my fave character!