Take a look at this great video put out by the UFC showing the top 20 knockouts from the first 20 years of the UFC.
Some of these are absolute classics. There are a few I was surprised missed the cut, but its hard to argue with the list the UFC put together:
A well known Rugby League writer, League Freak has established a reputation among supporters of the game for his fearless commentary and unmatched insight. With a reach that spans both sides of the globe, League Freak has produced an independent network that allows him to distribute content to his many thousands of followers. He is the owner and main author of LeagueFreak.com