When I am the Lead F/A, who makes most of the announcements, I keep it professional with no humor because usually what I am supposed to be saying are safety issues. BUT I love to kid around with the passengers in the main cabin during flight. I find that the F/C passengers are really all mainly business. They just want thier drinks/meals and then want to be left alone except for drink re-fills. of course, there are some exceptions in F/C, some believe THEY are the "comedy relief" for the flight, this would be the pax that rarely rides up front....lol