I've heard many good things about the Faeriewalker series, although I haven't read them myself. I especially love the covers of these books, Sirensong being my favorite.
Glimmerglass, although the darkness of the background threw me. The model is very pretty, and the smoke around her face is beautiful. I don't know if the dots are there for glitter, or if they're just fillers. I don't think they stand out as much as they do in Shadowspell. It's a very pretty cover, and I like the dark-light contrast that's going on.
(There's another companion novel, Remedial Magic, that's for Kindle on Amazon. Don't know if you have a Kindle, but if you're a fan and you do, here you go!)