After 13 seasons, Nickelodeon's SpongeBob SquarePants continues to infect households with joy and laughter. The asexual sea sponge premiered in 1999 and is the last remaining 90's Nicktoons series still airing new episodes. Almost as secret as the Krabby Patty formula, SpongeBob's secret formula for success is based on a simple but mighty premise, and a foolproof animated sitcom structure.