This art of Elsa is my favorite, and I already have a framed copy just waiting to go on my walls. It's an officially licensed image by Amy Mebberson. It's beautiful and makes me want to dress up like Elsa even more than I already did. You can get a print from Acme Archives Direct.
Kristoff, Anna, Olaf, and Sven look charming drawn in traditional 2D animation style. Besides this piece, artist David Kawena has a ton of wonderful Frozen art in his DeviantArt gallery.
Elsa, Anna, and animal/snowman pals in adorable chibi style. Eeek! This precious fanart is by TheKohakuDragon.
I know Elsa isn't a villain, but I still love this design of her as a Sith by Ralph Sevelius.
Swirling snow and curving lines and a beautiful sky. I love every pixel of this art by kowan.
I want to stuff some chocolate in my face. By littlegreenfrog.
Simple, pretty, perfect. I like this version of Anna by Valentina Pinto.