One of the first well-publicized episodes of "WTF with Marc Maron" was last june's interview with Dane Cook, where the two vastly different comedians had a lengthy conversation about their respective careers: Cook's of a "superstar comic" who sells out arenas but who generally receives less-than-positive sentiments from other comedians; and that of Maron, often heralded as a "comic's comic" (at least until he reached a wider audience with his mega-successful postcast).
Maron went on "Late Night with Jimmy Fallon" on Tuesday night to discuss "WTF" with Fallon. The highlight of the interview was Maron reenacting his phone conversation with Dane Cook before their interview. It may not be a hard task to make Jimmy Fallon crack up, but even he exceeded his normal levels of breaking up at Maron's Dane Cook impression. (Fallon himself was on "WTF" recently as well.)
Check out Maron's impression, which begins at around 0:53.