Just one of them from Atomic Trousers:
“COEXIST”(spelled out with various religious symbols)- If some of the followers of the religion represented by the crescent moon “c” on your cute little bumper sticker would stop hijacking planes and blowing up buildings, coexisting would be a little easier.
Which gave me the idea to make it a bit more realistic:
Coexist With The Commies And The Nazis, You Smug Little Twerp!
Raises the bar a little bit, eh?