One of the funniest things that my Prince (he's a Boxer dog) has done was his first " Boxer Burn"!
The first month we had him in our house, he started running around the dining room table about 30 times while we were playing with him. (Sometimes he runs back and forth down the hallway.) I started laughing so hard because I've never seen a dog do anything quite like that before! I still laugh when he does it!! I'm sure there'll be plenty of more boxer burns for his upcoming birthday (He'll be 3 years old on September 18th!) 
However, the thing that my former dog Zsa Zsa did (she was a toy poodle and passed away in May of 1995) totally beats out Prince's boxer burns! One time (I think I was in the 8th or 9th grade), I was doing a ballerina tip-toe twirl. When I looked down, Zsa Zsa was doing the same thing!! I could not believe it!! I wish could have had it on camcorder because that was a 'once-in-a-lifetime' moment!