Now, I know we're not supposed to judge books by covers, but, hell, we're gonna do it anyway. Good Comics is having a contest to pick the most iconic DC comic covers, and you can participate in the judging!
Not super interested in comic books? Omnivoricious put together a gallery of the best book covers of 2009, and the Book Cover Archive put together a list of the top ten book covers this decade. And, if you're not a huge fan of what they chose, check out the Book Cover Archive's archive.