The journey into the sociological study of rudeness often begins at the turnstile: People trying to rush out as you're rushing in. And then, there are the different behaviors once you're on the train: Some rude, others borderline gross.
How about the pole leaner; you know, the guy who's all sweaty leaning up against the pole because he doesn't want to hold on to it. Or the two-seater: the person who takes up two seats. And let's not forget the door chargers: those pushing their way on when you're just trying to get off!
Common courtesy does go a long way.
I gave an empty seat up to a guy who looked like he could use it much more than me. Some seemed stunned that I did.
But I didn't want to record too much, because that is kind of rude, too, and kind of creepy.
Bottom line, as one guy told me, is to just be aware.