Comedy Central
(launched in 1991 as a merger of The Comedy Channel [1989] and Ha! [1990])
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I guess I couldn't have had access to Comedy Central until I went to college in 1995. Since then, there have been a number of series I've watched with some regularity (and other things with irregularity). I've also seen any number of stand-up comedy performances on the network, but that was usually from random viewing, channel surfing or whatever, rather than regularly tuning into specific programs. The network has had various stand-up series, and I've probably seen bits of some of them, but I couldn't tell you with any certainty which ones I've seen. But probably I saw a bit of Comedy Central Presents, and Premium Blend, maybe other things. It's also possible I've seen some series that I've completely forgotten about... and certainly there are things that I watched at least one episode of but don't list here because I didn't really care about them. Oh, and of course there may be any number of syndicated shows or movies that I might have watched. (I also want to mention that in 1999 there were promos for the network by various comedians, like Mike Myers, and Janeane Garofalo. I should try to find those things for nostalgia.)
Politically Incorrect (7/25/1993 - 11/15/1996; moved to ABC, 1997-2002. I didn't see much of this)
Dr. Katz, Professional Therapist (5/28/1995 - 2/13/2002)
The Daily Show with Craig Kilborn (7/22/1996 - 12/17/1998)
Viva Variety (4/1/1997 - 12/1/1999; I didn't see much of this.)
Win Ben Stein's Money (7/28/1997 - 1/31/2003)
South Park (8/13/1997 - present)
The Daily Show with Jon Stewart (1/11/1999 - 8/6/2015)
Beat the Geeks (11/7/2001 - 10/7/2002)
Clerks (12/14/2002; two of the series' six episodes had aired on ABC in 2000)
Chappelle's Show (1/22/2003 - 7/23/2006; I saw occasional sketches)
Drawn Together (10/27/2004 - 11/14/2007; I saw one season of this, at most)
Mind of Mencia (7/6/2005 - 7/23/2008)
The Colbert Report (10/17/2005 - 12/18/2014)
Futurama (3/23/2008 - 9/4/2013, s5-7; s1-4 aired on Fox, 1999-2003)
A Colbert Christmas: The Greatest Gift of All (11/23/2008; special)
Krod Mandoon and the Flaming Sword of Fire (4/9/2009 - 5/7/2009; also aired on BBC 2)
Key & Peele (1/31/2012 - 9/9/2015)
All-Star Non-Denominational Christmas Special (11/27/2014; special)
The Nightly Show (1/19/2015 - 8/18/2016; I didn't see much of this)
Why? with Hannibal Buress (7/8/2015 - 8/26/2015; I'm not sure how much of this I saw)
Moonbeam City (9/16/2015 - 12/9/2015)
The Daily Show with Trevor Noah (9/28/2015 - present)
Corporate (1/17/2018 - 8/26/2020)
Desi Lydic: Abroad (5/13/2019; special)