There were four of us traveling on a Dash 8 on the way back to university after the holidays. We were seated across one of the 2 - 2 rows.
This obnoxious, big shot, stuffed-shirt businessman seated in the left aisle seat one row in front of us started giving the lone F/A a hard time as soon as we reached cruise altitude. He insisted alcoholic drinks should be provided free and when they were not, started cussing the F/A and the airline. She turned away from him and walked forward to the galley, but before she came back from the galley with the next tray of drinks, this guy put his feet on the armrest of the seat across the aisle to block her path and demanded free booze. She declined again and he moved his legs and let her pass, still cussing her. She did a good job igoring this and walked forward to the galley again. Then the guy shouted out "Waitress!! Where's my drink??" and put he feet on the armrest across the aisle again. Everyone aboard was looking at this guy now.
At this point one of my classmates, Keith said "This guy is really starting to make me mad." and he stood up and walked over to Mr. Big Shot. The other three of us got up and stood beside Keith. Keith is 6FT4, 240LBS, but the rest of us are 6FT, 200LBS anyway. Keith could not stand straight due to the low ceiling in the Dash 8 and the back of his head was against the ceiling when he leaned over Mr. Big Shot. All Keith said is "If you don't stop it, I'm gonna kick the shit out of you right here and now."
The guy took his feet of the armrest and didn't say a word for the rest of the flight. I'm sure the F/A must have wondered why he suddenly stopped acting like a complete idiot.
I still think a mid-air brawl would have been a more interesting outcome!