Not saying its the best or even should be ranked up there.
But, I always thought Cosmos had a cool little orbit feature on the backglass. Not the coolest. Just thought worth mentioning.
I really like Rocky & Bullwinkle and Friends backglass though, because it has 3 different animals to pull out of the hat and they correspond to the DMD and so its a little bit of variation.
And of course Scared Stiff Spider Wheel is really awesome. Anything that gets you to stop what you are doing and be able to take in the amazing backglass art for Scared Stiff is alright with me.