What are the best/worst things to say on an airplane?

In about a month I will be flying to visit some family. I started thinking of the most funny things that I could say on the airplane, that would get the guy behind me worried or utterly confused. I also started thinking of things that I shouldn’t say like “I’m carrying a bomb and I am going to blow up this flight!”

What do you think would be the best/worst thing that I could say in flight?