I love Wiggum. 
"Wow chief, the dogs sure do look angry"
"Yeah, I've been teasing them, singing off key. Mee, may, ma, mo... mee, moo, mah, may"
Another one I had a look for, think it's from a newish epsiode.
Wiggum is up a tree in the cemetary, completely naked and shaking. They can't talk him down. Lou goes "I hear they just cooked up a fresh batch of donuts." All of a sudden Wiggum is standing at the bottom of the tree, fully clothed and with a very composed demeanor and says "Let's Roll"
Nearly p*ssed myself at that, especially since I'd long given up hope of much really brilliant stuff coming from them in these later series.