The first time I ever saw a ticker-tape parade after the Yankees won the world series in 2000, I assumed NYC would be covered in paper for months. Everything was completely covered in paper! By the next morning you couldn't tell anything happened. Not a single scrap of paper anywhere on the streets or sidewalks.
Same thing after the annual West Indian Parade. After the parade, the streets of Canarsie are absolutely taken over by people partying, dancing, drinking, the floats pass back through the neighborhood, and it's just complete chaos. Next day: like nothing happened.
They have garbage cans on every corner, and most are managed regularly enough. My wife is from Queens and she constantly complains about how hard it is to find a public garbage can in Chicago. I never realized it before, but she'd absolutely right.
Also their snow is handled far more efficiently - even if you don't have an alderman or police chief on your block.
NYC is definitely dirtier than Chicago, but it's pretty damned clean, considering how many people there are in such a small space.