The game is called 'king of the hill'. Basically the first person is the king of the hill, the next person in the topic has to do something so that he becomes the king of the hill. Example:

Person A: I'm King of the Hill! Person B: I pushed you down. Now I'm King of the hill.

Ok I'll start. I'm King of the hill

P.S. Stop with the shoving off and add in some creativity.