This first book of The Secrets of the Immortal Nicholas Flamel series is pretty good.
It depicts an interesting world that takes place right now, in the beginning of the twenty-first century (cell phones! Laptop computers! iPods!), and that mixes mythologies of various traditions (Egyptian goddesses, Celtic legends, the ever-popular Atlantis trope and the Norse world-tree of Yggdrasill all make an appearance) with the usual YA fantasy novel landmarks: our protagonists, Josh and Sophie, are two fifteen-year-olds twins, they are the Chosen Ones (okay, the prophesied ones), and they have out-of-this-world amazing magical potential. Also, their mentor is Nicholas Flamel, you know, that super-famous French alchemist who also had a mention in Harry Potter and the Philosopher's Stone. Or Harry Potter and the Sorcerer's Stone, if you're American.
I liked it; I think this series has a lot of potential for character growth and complexity, and come on, there's mythology involved! Plus, the cover art's pretty cool. It even looks good on my battered softcover public library's copy!