Tweefight, which relies on Tweerank to build the data, let’s you have some fun by putting any two twitter id’s against each other. It then computes the winner based on the following:
# of tweets
# of RT he/she receives
# of replies
# of distinct users who reply
# of distinct users who retweet
# of RT the user makes
# of links the user shares
The fun part is to make some money on the site, they allow you to buy (for under a buck) some added powers to help you win. Now i you put in some name that is a beginer in Twitter versus, oh Oprah, we know the outcome already. But when they are close in friends and followers it gets interesting.
They let you see the World Champion (Zaibatsu right now), Top 20, Hall of Fame and even your own stats page. Give it a shot.