They don't have to be funny all the time, but cool will probably matter since noone will care what you post

These 2 stand out to me. The first, straight, to the point, and does everything a slogan should do.

"The game of world domination" - Risk

Thanks Douche for giving me this idea

Another is:

"A monument of inefficiency." -Rally's(I think)

In case you don't know, Rally's is a fast food chain. They were talking about their hamburgers and how they take their time with them.