The "Good Show Sir" blog is devoted to bad covers from science fiction and fantasy books. And some of them are really bad, like, I think, the one above. But some strike me as just ordinary, like the one below. Not a great triumph of design, but the picture is skillfully rendered and not ridiculous. Fortunately the site provides a way for readers to vote on the covers, and you can see that while the worst ones score more than nine out of ten, some of the unobjectionable ones have scores in the range of 3 to 4.