Homeless people. Sure, their lives are rough, but some of the stuff they say or do just stands out.
When I was having a smoke, a homeless guy approached me so he can tell me how unhealthy tobacco is. He recommended weed over tobacco, and his justification was that tobacco dehydrates you.
Another time, some stupid kid threw a rock at a homeless person on a bike. He fell off his bike, so in his blind rage he threw the bike at the kid.
And finally, when I used to work at Toys "R" Us, some bum tried to steal an Xbox 360 console. He was about to make a run for it towards the emergency exit, but my co-worker spotted him. Since he was caught, he came up to my cash register, pretending he was interested in purchasing the console. He was the funniest looking guy I've ever seen, he reaked of cigarettes and urine, had a large, grey, dirty beard, and wore a white cap with a black brim with a golden anchor symbol on the front and the word "CAPTAIN" above it. Yeah, he sure was subtle.
^ is so much win!