I was in the mood for a new dashboard theme this weekend so I went to the Marketplace and thought, "This Fun Fur one looks like it would be cute." Mistake!!! This theme was not cute, it was scary. So now I was out points...sheesh...
Discussing (ok, I was whining) to a friend that there should be previews available before you buy, he said that there were previews available at Xbox.com. (Figures) So here is a link for anyone else that didn't know (although I was probably the only one that never thought to look).
http://www.xbox.com/en-US/live/marketplace/themes.htm
I couldn't find a page with all the available themes on it (so if you know of one, let me know!) but I did find one with the newer themes that you can preview before you buy.
ICandee