+10 for people in general
+1000 for people getting in line to board when they are zone 2 and it is still pre-boarding. Same for first class when announcement hasn't even been made. Your seats are assigned no need to cause a traffic jam and slow the process.
Loud talkers, I don't want to hear about your life from four rows away.
Arriving "early" only to sit on the tarmac until arrival time because the gate isn't available.