What are some TV shows where every season was great.

[Smashius Clay]

Nothing live-action comes to mind. There's plenty of Anime that's flawless tho.

 

[Tetsuo]

Nikita

 

[semicko82]

Mad Men
Breaking Bad
The Wire

 

[DaylitoJames]

The Shield
Justified

 

[nose hair]

Star Trek: The Next Generation

 

[Flywin Lannister]

So far....

but the Jury is still out on

The jury has returned a verdict: the last season was mediocre at best

 

[MaxBundles]

Prison Break
Bates Motel

 

[MikelArteta]

Spartacus

 

[Lurking Class Hero]

Peep Show

 

[semicko82]

Mad Men
Breaking Bad
The Wire

Add Better Call Saul to this list.
I wanted to put Battlestar Galactica but the tail end of the last season was

In hindsight Sopranos never had a bad season. Although I wasn't to crazy about season 6a