Shows that get better as the seasons go on?

There are a lot of shows that start out incredibly, before steadily declining as the seasons span on and on (Lost, The Walking Dead, etc.). Or some that start off good, reach a peak midway through and then fall off a cliff towards the end (Game of Thrones).

But are there any that start off good, and just keep getting better and better right until the show finishes? The main one I can think of is Breaking Bad. And hopefully Stranger Things if the final season delivers!