How about
for some on planes:
People who give up their F seats for military folks seated in Y.
People who give others their tablet (with movies) for the flight when the recipient realizes that there's no IFE.
People who make unsolicited offers to swap seats when they see a party not seated together.
Most of the time, it's the pros that do these kinds of things. It's the "sense-of-entitlement-because-I-paid-$300-for-my-ticket" folks that seem to overpopulate the inconsiderate crowd.
Now, seat-recliners? There's a special level of hell reserved just for them. I'm fairly tall and make sure that if someone reclines their seat without even bothering to check to see if there's a 98th-percentile tall person behind them, they get the courtesy of my knees jammed in their back for the duration of the flight.