The Lightning Thief -- Rick Riordan
In a way, it's nice to know there are Greek gods out there, because you have someone to blame when things go wrong. For instance, when you're walking away from a bus that's just been attacked by monster hags and blown up by lightning, and it's raining on top of everything else, most people might think that's just really bad luck; when you're a half-blood, you understand that some divine force really is trying to mess up your day.
Super fun. Potter fans will really like it. I know, I know. Someone says that about every single fantasy novel that's been published (or re-published) since HP, but dammit, it's true.
The similarities are mostly just broad plot points -- odd things happen to a boy throughout his childhood, he ends up at a summer camp for special kids where his immediate support group is comprised of another boy and a girl.
The tone is different, though. It's much more snarky and breezy than the Potter books, and the details are very different: It turns out that Camp Half-Blood is a summer camp for kids who are directly descended from the Greek gods. (Directly as in: The Children of.) I especially loved this fact: Due to his bloodline, Percy's brain is hardwired for Ancient Greek and battle -- which translates to dyslexia and ADHD in a regular classroom.
As there's a trident on the front cover and Percy shows his power over water pretty early on, it isn't particularly difficult to figure out Percy's dad's identity. I also had the turncoat identified, but not the Big Bad.
The book's wonderful chapter headings ("I Accidentally Vaporize My Pre-Algebra Teacher", "Grover Unexpectedly Loses His Pants", "I Become Supreme Lord of the Bathroom", "I Ruin a Perfectly Good Bus" and (my favorite) "I Battle My Jerk Relative"), brilliant character descriptions:
Grover was an easy target. He was scrawny. He cried when he got frustrated. He must've been held back several grades, because he was the only sixth grader with acne and the start of a wispy beard on his chin. On top of all that, he was crippled. He had a note excusing him from PE for the rest of his life because he had some kind of muscular disease in his legs. He walked funny, like every step hurt him, but don't let that fool you. You should've seen him run when it was enchilada day in the cafeteria.
and fresh and original action descriptions:
Grover went flying sideways down the hill like a possessed lawn mower, heading toward the van.
all made me wish I'd gone ahead and bought the sequel for super cheap when I had the chance.