1. Adventure Time
View this video on YouTube
That's right — our favorite dog-and-human pair started their journey on the good ol' Internet. Pendleton Ward created this seven-minute pilot almost entirely by himself, and it aired on Nicktoons in 2008. Sadly, Nicktoons passed on the show. But! The short thrived on the Internet, and a gazillion fans cried out for more. Cartoon Network picked it up, and the rest is history.
2. Human Giant
View this video on YouTube
Because of Aziz Ansari's heavy involvement in NBC's Parks & Recreation, the popular sketch show Human Giant only lasted two seasons despite MTV offering them a third. It's not well known, however, that Paul Scheer, Rob Huebel, Aziz Ansari, and the lesser-known Jason Woliner were doing Internet sketch comedy together well before Human Giant was picked up. (Take a look at Shutterbugs.)
3. Portlandia
View this video on YouTube
Set in Portland, Portlandia is a scripted and improvised sketch show created by and starring Fred Armisen and Carrie Brownstein. IFC picked it up in 2011, but Fred and Carrie had been collaborating for a long time before that happened. You can see a lot of their sketches (many of which made it to Portlandia) under their original name —ThunderAnt.
4. Kroll Show
View this video on YouTube
Nick Kroll completely nails it on the character front. So much so that Comedy Central gave him his own sketch show last year. If you dig deep enough, you can find Kroll fleshing out these characters over the past few years on the Internet. Bobby Bottleservice was a web series, and the podcast Comedy Bang! Bang! features the early days of many a Kroll character.
5. Rick and Morty
View this video on YouTube
This animated series premiered on Adult Swim only a few months ago, and it's already gained a devoted following. The show actually started as a short film called "Doc and Mharti" — and after it attracted a whole bunch of Internet attention, creator Justin Roiland teamed up with Dan Harmon to create the show as we know it today.
6. Workaholics
View this video on YouTube
Before the mega-popular Comedy Central show Workaholics demanded that you "Be Fresh," Adam DeVine, Blake Anderson, and Anders Holm had a sketch comedy group called Mail Order Comedy 'round about 2005. Look how young!
7. Drunk History
View this video on YouTube
Hard to believe that a show focused around getting comedians intoxicated and re-dubbing their drunken historical storytelling could be so hilarious, but it is. Drunk History is one season in, and it's already got an incredible list of cameos. This is mostly because of creator Derek Waters' successful web series of the same name. Check out the first online episode above, and then devour the rest.
8. $#*! My Dad Says
"I didn't say you were ugly. I said your girlfriend is better looking than you, and standing next to her, you look ugly."
This 2010 CBS show may be the first sitcom to ever be based off of a Twitter feed. Starring William Shatner, the show is loosely based on Justin Halpern's Twitter account of the same name. (Well, the uncensored version of the name.) Justin moved back to his parents' house in 2009 and started documenting his father's comments on Twitter — it gained a massive following, and the rest is history.
9. Childrens Hospital
View this video on YouTube
Before Adult Swim picked up this absurdly hilarious faux medical drama, it was a web series on TheWB.com. That was late in 2008. Today, the show is four years into a successful run.
10. Broad City
View this video on YouTube
Broad City is a brand-new show on Comedy Central that is based off of a web series of the same name. The web series, created by Ilana Glazer and Abbi Jacobson, has been going strong since 2010. It's about two girls in their twenties living in New York City, and so is their new show. Oh, and Amy Poehler produces it!
11. Billy on the Street
View this video on YouTube
After Funny or Die's Billy on the Street web series gained a huge following, Fuse TV picked it up and gave it a shot in 2011. Billy Eichner stars in this game-show-themed program — essentially he goes out on the streets of NYC and asks pedestrians pop culture trivia questions. This March, it will be entering its third season.