What classic space opera novel do you want to see on the big screen?S

If the Ender's Game movie is a success, then maybe the floodgates will open for other classic space opera books to hit the big screen and rock our universe. What classic space opera novel (or book series) do you think would make a fantastic movie nowadays?

Please include a cover image or some other cool picture, so we can admire the coolness of your space opera choice!

Top image: Chris Foss artwork, for (I think) Isaac Asimov's Foundation.