Greatest Philosopher of the 20th Century?

Here's a recent discussion of who the greatest philosopher of the 20th century was:
(I won't ruin the suspense by giving it away before you read it--)

http://leiterreports.typepad.com/blog/2009/03/lets-settle-this-once-and-for-all-who-really-was-the-greatest-philosopher-of-the-20thcentury.html