Can you picture Late Show with David Letterman bandleader Paul Shaffer as George Costanza on Seinfeld? He was actually offered the role but turned it down, according to Shaffer's new book, We'll Be Here For The Rest Of Our Lives.

Now, this isn't one of those situations where a group of people were brought in to audition for the role, Jerry Seinfeld actually told him he didn't have to audition for the role, the role was his, he just had to accept it. But Shaffer didn't call back because he was too busy with other jobs. It wouldn't have been the first sitcom role for Shaffer. He co-starred in the 1977 show A Year at the Top, with Mickey Rooney and Greg Evigan.

It's easy to say that Shaffer wouldn't have been as good as Jason Alexander, but we don't really know that, because Shaffer would have taken the role and done it his way and Alexander wouldn't even be in your heads. But Alexander really did make the character his. I bet he wouldn't have been as frantic and paranoid though.