Call it what you will, the boys shut a hellmouth.
That’s being slightly churlish though since the creators have set up a fine ending though. Even the get out of jail card free card wasn’t entirely played and the balance is still there but what Dean now he’s made his deal? They’ve destroyed the demon who they’ve have been hunting since the beginning but no happy ending.
Has Jo been kept to replace one of them since the year runs out at the end of Season 3? Let the war begin in earnest…