Here are a few non-Etsy sites for Christmas cards.
The first is from Blonde Designs. This company is run by two former art directors from Martha Stewart Living. Their designs are perfectly simple.
This beautiful wreath card from Paper Cafe who I have mentioned before.
Beautiful wooden letterpressed cards from Cotton Idea Studio
Tiny Prints always has great cards. I had a hard time just picking one that I liked.
Last but not least, this pretty card by Cocoblu Studios