I'm from the suburbs, but in downtown Chicago (where I went for college)
-There's a guy nicknamed the "Hi Guy" , who wears smiley face clothing and items head to toe, and on his bike, while he bikes around the city. I haven't seen him for a few years though .
-There's also a guy named Vincent who wears crazy colorful suits and dances around in front of the ABC 7 building and bridges. Here's a whole article, and another one with videos on him .
http://www.rogerebert.com/rogers-journal/vincent-p-falk-and-his-amazing-technicolor-dream-coats
http://zweeblefilms.wordpress.com
- Last but on least, there's a man, whos jehovah's witness , and preaches over a microphone , in front of a Old Navy. He preaches that everyone has to repent or something will happen to them in the rapture, basically .My grandma, who's 86 now, used to work downtown as a banker and says he was there back when she worked by there... No idea how old the guy is, but wow. That's commitment.
Chicago has a lot of characters, I've also seen a homeless man dressed as a pirate , a different homeless man with mental issues, who roars at a corner. There's also a man who compliments people and calls woman 'Cleopatra' and 'Aphrodite', right by a breakfast restaurant.
Edit: Ooh there's also a big open field down by the 'downtown' area of my town, that tends to get filled with homeless people. I nicknamed it 'Bum Fields' and it seemed to stick with some people.