This episode was a stroke of genius by Trey and Matt. At the end of Season One they put a cliffhanger - who is Cartman's real father? - and told viewers to tune in next season to find out. But then at the beginning of Season Two they aired a full episode of Terrence and Phillip instead! Apparently they received many complaints by angry fans who were dying to see what happened with Cartman's father, but down the road it really was a stroke of genius and a daring thing to do. Most shows would never be able to get away with something like that. It's a great example of comedians manipulating and playing their audiences - much in the same way that Andy Kaufman used to - by using extended practical jokes.
The episode itself was hailed by Matt and Trey as their favorite of all-time on the Season Two DVD, but I think they were both being sarcastic (nevertheless, this "trivia" note made it onto IMDb). It's a weird episode purely because South Park and its residents - most noticeably Kyle, Stan, Kenny and Cartman - are completely absent and it's all just a Terrence and Phillip episode. So it gets a bit old after a while, but it's mostly funny for its back story.
The episode itself was hailed by Matt and Trey as their favorite of all-time on the Season Two DVD, but I think they were both being sarcastic (nevertheless, this "trivia" note made it onto IMDb). It's a weird episode purely because South Park and its residents - most noticeably Kyle, Stan, Kenny and Cartman - are completely absent and it's all just a Terrence and Phillip episode. So it gets a bit old after a while, but it's mostly funny for its back story.