Degrassi: The Next Generation. I loved Degrassi Junior High and Degrassi High, and I was skeptical of Degrassi: TNG, but it quickly became one of my favourite shows as it had very good writing, placing it above many teen drama shows. It was also unique in that some pivotal characters from Degrassi JH and Degrassi High appeared in it in important roles and not simply as background characters, so it had something for older fans as well. I stopped watching though when Season 8 started as it was a completely new cast of juniors. When your cast has moved on, and you don't recognize half the people on the show, I think it's safe to say it's time to put a fork in it. They should learn from Saved by The Bell: The New Class. That didn't end well.