The single greatest voicemail greeting in the history of voicemail -- George Costanza's "Believe it or not, George isn't at home." Sorry, no matter how clever you think yours is, George had you beat in 1996. Kat Dennings was on The Late Late Show with Jason Alexander last Friday and admitted that she had George's message as her voicemail greeting and how it was a bit confusing for people. Jason Alexander took it upon himself to update her voicemail message with a personalized version of the song. And that's how Kat Dennings got the best voicemail ever. 

And here's George's original voicemail message adapted from The Greatest American Hero.