"Invader Zim" is still one of the best shows to be made in my opinion however, the show was quickly cancelled at the beginning of its second season in the early 2000s by Nickelodeon. No one really knows the official reason why the show was cancelled other than the producers themselves although there have been many theories suggested by former fans of the series. "Invader Zim" was definately not a children's show by most modern standards, which some people claim to be the fate of the show, however, this theory comes from modern standards. "Invader Zim" had some very intense humor including dirty innuendos and even gallows humor. Although comedy about tragedies had been unheard of in the animation industry, sexual innuendos were definately common, especially during Nickelodeon's highest point in the 1990s. Shows like "Rocko's Modern Life" pushed the limit of what the F.C.C. would allow to air on T.V. Some episodes were even banned from ever being aired because of how perverted they were, including one where Rocko is seduced by an older woman, yet it was never cancelled for its extreme use of comedy. I believe "Invader Zim" was cancelled due to its poor ratings because of the market they were in, The show played in an awkward tone between comedy, suspense, and science fiction. It was almost like an episode of "The Twilight Zone". This is something that the animation industry, especially children's shows, rarely ever expand into. Children simply don't like it and I feel that "Invader Zim" was simply in the wrong market. Maybe the show would have survived if it were in a different market. It may have even found a place on Adult Swim although we'll never truly know. Like most Nickelodeon classics of yesterday, "Invader Zim" has left its cultural mark on society today. I still find references to the clumsy and humorous Gir, Zim's robot. I really do miss this show and I thought it was absolutely great. It's been quite awhile since I've last seen it, but I'd reccomend anyone to watch at least one episode.