I may have only said this a few hundred times but I'm a HUGE fan of Jennifer L. Armentrout's books and I cannot urge you enough to read them, especially Obsidian which is SO HOT, you could cook your dinner off it. And yes, it's Young Adult but I think it's a really nice crossover title and if you're interested, my review is here.
Obsidian is still one of my favourite books and Jennifer recently got together with the cover models and made a book trailer. If this doesn't make you want to read the book? I don't know what will ;)