Not sure if it's been mentioned already, but...the "Harbinger" trilogy by Diane Duane. Basically, a series set in one of TSR's (now Wizards of the Coast) role-playing game universes. I hadn't heard of the game before the books came out, but absolutely loved the books. Just found out recently that the company has the rights to the books and has no real interest in releasing ebook copies, which is sad