I love a good fairytale -- from the originals to the retellings (like Cinder) to the mashups (Cruel Beauty) to the fantasy verions (500 Kingdoms Series). I've been a fan all my life and they seem to be coming into a bit of popularity in the YA genre. Here are my favorites, both YA and not.
Bitter Greens by Kate Forsyth
Cruel Beauty by Rosamund Hodge
Cinder/Scarlet/Cress by Marissa Meyer
Kill Me Softly/Tear Me Apart by Sarah Cross
Shadows on the Moon by Zoe Marriott
Ella Enchanted by Gail Carson Levine
The Black Swan by Mercedes Lackey