I love any sort of listing of books, for whatever reason. they're invariably and by design argument starters, because YMMV on just about any art opinion.
This list especially seemed skewed, because it's a list of the "coolest" book covers. Whatever a "definitive" list of this ilk would be, it would probably have to include a bunch of dud books, made popular solely by the book design. And they'd probably have to exclude books that became famous under different covers -- I loved and am still haunted by The Road, but I didn't read it under the cover that's incldued here. As great as that cover is, ti's nto what I associate with that book.
I could go on blogviating -- I'm sure I can't be the first person to make up that word -- but I'll cut it short to comment on one salient point: Super Mario made the list. Props to Dan Donohue for eight-bitting the hardcover dust jacekt, up and keeping things iconic.
Another reason to love these lists is it lets me play the how-many-have-I-read game. I've read 18 of the 50, including my own book too many times to count. Only counting it as one, though.