While visiting Jimmy Kimmel Live, Britney Spears and Simon Cowell dished on the premiere of the X Factor ... and discussed the possibility of Khloe Kardashian becoming host. Not sure if Kim's younger sister will appreciate being labeled a "trainwreck." Yikes!

And, of course, Mr. Kimmel had the X Factor judges play the Newly-X Game. When asked about Britney's best asset, Simon doesn't hold back.

Gotta love live TV!