The longest-running show on Comedy Central debuted July 21, 1996 -- 15 years ago this week. Jon Stewart became host of "The Daily Show" in 1999, and has been commenting on the media ever since. Stewart, who has often been compared to broadcast news icon Edward R. Murrow, insists he is not a journalist but holds accountable those who are. Stewart and his staff are serious about media criticism, as they told Mallary Tenore in 2009. Here are highlights of the show's media criticism through the years.

2011: Stewart appears on "Fox News Sunday" and on "The O'Reilly Factor." (He also appeared on the show in 2010.) Stewart has often criticized Fox, starting in 2002, when he told Howard Kurtz on CNN's "Reliable Sources," "It’s clearly meant to be more ideological and more opinion-based."

2009: Jon Stewart mocks The New York Times over the years, most famously in this segment filmed at the paper:

Also in 2009, Jon Stewart takes on CNBC, Jim Cramer over financial crisis coverage.

“I understand you want to make finance entertaining, but it's not a f-ing game. When I watch that, I can't tell you how angry that makes me."

2004: Jon Stewart takes on Tucker Carlson about "Crossfire," which was canceled a few months later.

STEWART: You know, the interesting thing I have is, you have a responsibility to the public discourse, and you fail miserably.
CARLSON: You need to get a job at a journalism school, I think.
STEWART: You need to go to one.

2004: Jon Stewart takes on Robert Novak about his role in leak of CIA operative Valerie Plame's name. Novak died in 2009.

“He leaked a CIA source for punitive reasons – for ugly, partisan purposes.”