The Simpsons has entered its 28th season and just hit the milestone that is so rarely achieved by scripted TV shows: 600 episodes. It has taken the title from "Lassie" as the second longest running scripted series. They will need to get to 635 episdoes to beat "Gunsmoke" but it is already one of only two television shows in history to reach 600 episodes. The show has been running since 1989 and has become a staple in pop culture references. Here are 28 of the best moments we can remember from the series to celebrate it's 600th episode and 28 seasons!