Not really the toughest, but...
About a year ago I was on a subway platform and heard a pretty dumpy looking guy make a cat call to a good looking woman:
She immediately stopped in her tracks, spun on a heel, gave a long neck roll and started a tirade that went something like this:
Do YOU want to talk to ME?
You want to talk? Alright. Let's talk.
Let's talk about YOU instead.
Let's talk about your yellow teeth.
Let's talk about your beat up timberlands.
What about your dirty clothes?
Etc. Etc. The dude started walking away from HER and frankly, as funny and redemptive as I found the woman's riposte, I was a little embarrassed for him. Then, the woman decided to let it go, and finished with Shakespearean volume:
WELCOME TO NEW YORK CITY. THE TOUGHEST CITY IN THE WORLD!
Today, not disimilarly, I was walking through SoHo, thinking about crazy Tokyo fashion (who isn't?), when in the distance I saw a crew of GLAY-lookalikes who had clearly just gotten off a flight from Narita. I thought, "wow. Harajuku halloween," upon eavesdropping, they did not fail. They were "cool."
Glay 1: That was a sick shirt.
Glay 2: Man, for real.
Glay 3: Hey guys, I gotta take a mad piss, like, now, dude.
These are approximate translations, mind you, but just take my word for it. These were confident young men (in skin-tight pleather pants and wearing eyeliner).
Fast forward a block to them walking past a group of NYC SCHOOL CHILDREN who literally, point, and, laugh. Glay went dead silent.
It's a tough city, my friends.