We have a turtle on ours. That's it. I like turtles. It reminds me of Hawaii and I love it there. That's about it!
As for others' bumper stickers... I enjoy reading them and then seeing if the person inside matches my predetermined idea of what they must look like. I'm usually spot on!
It's funny, I am REALLY opinionated on almost everything, but I find political stickers to be so distasteful - as if they're just sort of embarassing. Especially stickers for candidates that lost. But those are also funny... Heh. I guess I'm just a jerk.