escape yourself and gravity

I stopped watching CM when it aired years ago, and just buy the seasons when they come out. Would you recommend stopping at the last season? (which I haven't finished watching) It wouldn't be the first time I've had a cut off point with a show. I think tv shows should have expiration dates, let them go out while they're still good, instead of dragging terrible episodes on for years. "cough" CSIs "cough"