I'm from NJ but currently go to school in MD, so it's interesting to hear people from different states use different names. At home though, whenever I talk about weed I just call it "trees".

Jersey:
headies
beasters
mids
dirt

Maryland:
KB
mids

However, I've never gotten good weed in MD, everything that is KB is like beasters. Very annoying. Jersey on the other hand....mmmmm. I can't wait till I get to take a trip home again.