Clone High

Warning: Plot details follow.
Clone High was set in a high school which was secretly being run as a military experiment. The school was entirely populated by clones of famous historical figures, to be later used by the military, who would harness their greatness in battle. The principal of the high school, Principal Scudworth, however, had his own plans for the clones (he was something of a mad scientist figure). He was assisted by his robot/vice-principal/de-humidifier Mr. Butlertron.
The main protagonists of Clone High were clones of Abraham Lincoln, Joan of Arc, and Mahatma Gandhi. Much of the plot of the show revolved around the attempts of Abe to woo the self-loving and promiscuous Cleopatra, entirely ignorant of the fact that Joan of Arc (presented as a liberal goth girl) is attracted to him. Meanwhile, John F. Kennedy (always named "JFK" in the show) is also attempting to win over Cleopatra.
Many celebrities, including Tom Green, Mandy Moore, Marilyn Manson and Jack Black, made guest appearances on the show (sometimes as themselves). There were also many amusing portrayals of famous historical figures, Ghengis Khan, George Washington Carver, and even Jesus Christ (as JesÃÂús Cristo).
Much of the humor in the show comes from the interaction between the historical figures. For instance, Gandhi is portrayed as a hyperactive jerk-with-a-heart-of-gold whose biggest dream is to be accepted by those around him, in contrast to his historical legacy of calm nonviolence.
The show is also a parody of "issue" episodes of high-school themed comedies. For example, an episode centered around Gandhi being shunned by his school for having ADD because of misinformation about the disease, parodying "very special episodes" of TV shows which tackle AIDS awareness (it even included a special guest celebrity who tries to educate the students). Other episodes tackle drugs, the environment, and drinking in a similarly ridiculous fashion. In a clear sign that it is parodying the high school genre, it even ends at prom--a stereotypical "high school show" ending. However, there were also many straight-out gags.