"Why is it that the people with the worst seat in the party always want to switch for the better seat?"

I like that. My FAVORITE in this category is the family of 4 (or 5 or 6 or...) on a Southwest flight that show up at the gate just before they close the door and has nothing left but 4 (or 5 or..) assorted middle seats throughout the plane. Then they start complaining to the FA (usually after they complain that there is no space for their overloaded Hefty bags full of clothes). Then the FA gets the task of begging enough people to give up non-exit row aisles/middles to accommodate them. I've seen this happen with several families at once. What a nightmare.

I absolutely love replying:

"That's why I got here an hour before the flight."

Southwest should put on their tickets: "IF YOU HAVE REASON TO PRE-BOARD YOU MUST CHECK-IN 20 MINUTES BEFORE TAKEOFF", instead of the usual 10.