I have very few pet peeves, the first being when people refuse to use their turn signals (all of California) and the second being when people on public transit don't give up their seats to people who need them.
This girl got on the train carrying these absurdly large boxes and looked around for somewhere to sit. I'm standing with my bike and think... Surely. Surely someone's going to offer her a seat. I glare at the twenty something year old dude sitting in a prime front seat. He glares back at me. I glance at the girl who is struggling to stand as the train moves back and forth and then glance back at the guy. He doesn't budge. A few other younger people are staring at the wall. Finally someone gets off the train and she can sit down.