Angelbound, by Christina Bauer

This book is quite odd.  The hero is Myla Lewis, a high school senior in -- wait for it -- Purgatory.  She's a half-demon.  Has a tail.  And has a side job of fighting evil souls.

If you're not weirded-out just yet, then you might enjoy this novel.  I can't tell if it is youth fiction or even quasi-romance.  Then again, with a plot line like this one has, I can't tell much.  Still though, it was surprisingly enjoyable.

Angelbound