Check out this glorious page of Penguin sci-fi cover art. There's so much pretty!
I know I'm anything but alone in my appreciation of these and I love it when people with more time and talent than me take that love and do something fun with it.
So, with that in mind, you might like to have a look at these pages of Doctor Who stories reimagined as Penguin books - http://doctorwhopenguin.tumblr.com.
Kudos to all involved.