Along the same lines as this, my biggest pet peeve (in general and on the subway) is when you're traveling at rush hour, and everyone is standing really close together - but everyone is bunched at the door, because people refuse to look behind them or around them and see that in the middle of the train, there are often big holes they can move to to allow people to actually fit onto the car.
On several occasions, I've asked people to move over. Some refuse, and others do it then glare at me. Is it such an evil request? It's just common sense! People are SO STUPID.
"If you are going to do something, do it well. And leave something witchy."
-Charlie Manson