Possibly the funniest thing I have ever seen in chess was during a local tournament a few years ago. I was there, but not involved in the actual incident. Fortunately, as you will see, I was several tables away.
There was a woman, or perhaps I should say a girl, who was well known for her aloofness and lack of sportsmanship. It was quite strange, since her playing ability did not warrant any arrogance at all. But I digress...
Said woman was matched against a local master who moved to the U.S. from Russia and never bothered to learn English. This entertaining fellow has great white tufts of hair coming out of his head in no particular order, and constantly mutters under his breath in Russian. He is among my favorite players to watch.
The woman played on in a clearly lost position, and dragged out the time on her clock. According to the laws of chess, this is legal, but it's also widely accepted that it is totally rude. Especially when there is an 800 point rating difference between the two players.
Finally, the Russian managed to checkmate her, and moved to, perhaps reluctantly, shake her hand. The woman just sat there staring at him, unmoving. At this point, most of the people in the room (including myself) were watching. The master's face went beet red. He picked up his king, muttered something in Russian (which I can only assume was in the vernacular) and threw the piece at her as he stormed from the room.
The entire room burst into laughter (Which is truly rare at a chess tournament) and, I heard told later, the woman withdrew from the tournament shortly thereafter.
Maybe you need to be a chess player to appreciate this story, but I think it's hilarious.