And he reveals a top 10 list he submitted 17 years ago.
Stephen Colbert joined David Letterman on The Late Show on Tuesday for the first time since it was announced he's taking over the show in 2015.
David Letterman / Via Twitter: @Letterman
The current host introduced the "very talented, always entertaining" Colbert, who took in what could be his new office...
But we won't know where exactly Colbert's Late Show will film just yet.
CBS
And even Letterman noticed it suited him.
CBS
