Which shows got significantly better over time?

[Chavo Classic]

As opposed to the thread about shows that are/went past their prime, which shows started off weak and then exploded in later seasons? The type of shows that peaked around season 4, 5 or even 6 maybe, or were unwatchable at first and turned it around later on.

Shows like Archer and Justified for me didn't really start grabbing my attention until the latest season. I would always watch them, but it's only lately when I've been excited about seeing them. They're now first on my download list.

Parks and Rec had a terrible first season, and put me off watching. It wasn't until season 3 when a friend recommended the show again that I bothered. Even then, I was told that season one was a chore to get through, but still worth it for the next few.