The Odyssey Online came up with this great list of Urban Slang terms that are VERY New York. If you're true New Yorker you should know almost all of these. The first 7 are below, to get the rest to this link: Full List Of Urban Slang Terms
1. Whack = (adj) used to describe something that is appalling in nature
"That's whack!"
2. Grill = (v) to stare, usually impolitely; to give a dirty look
"Dude stop grilling my girlfriend, I know her spray tan looks whack."
3. To front/Fronting = (v) to put on a façade; acting like you are something that you are not.
"Stop fronting like you own the place."
4. Cop = (v) to buy
"I'm about to cop some chips, you want some?"
5. Catch these hands = phrase used to initiate a fight
"If that girl keeps grilling me she can catch these hands."
Variations: throw these hands; throw hands; catch this fade
6. Crusty = (adj) used to describe someone who is dirty or trashy
"Girl, did you shower today? Your hair is looking all types of musty, dusty, and crusty."
Synonyms: musty; dusty
7. Lit = (adj) used to describe someone or something that is amazing in every sense
Variations: litty