Are shows in your top tier the highest quality, or did they literally precipitate some kind of shift? Or both?
I'd say both?
These are the ones that people associate the term, "Second Golden Age of Television" most closely with, the ones I predict will stand the test of time.
You're missing The Office.
It's there in the third tier/The Outliers. Just not very high. (Sorry, 1S0).
The 2nd Tier: The Essentials
DOWNTON ABBEY
4th Tier: The Standards
I've watched all four seasons of this program and I wouldn't consider it an essential TV program. The first season was great, even with the episode plagiarizing Mrs. Miniver. But subsequent seasons have seen a steady drop in quality, with this last season becoming pretty trite. At first, I thought it was me, because during the hiatus between seasons 3 & 4, I watched all five seasons of Upstairs, Downstairs, a much superior Edwardian Age effort. But then I spoke to close to a dozen fans of DA, and they all seemed to think it jumped the shark, starting in season 3.
I think it belongs in the 4th category
Julian Fellowes, Maggie Smith, the big crossover appeal it had, etc. were all factors that made it climb so high. I watched only the first season, so I am not 100% sure where it should be, but I think I am going to compromise and put it in 3rd since it has dropped in quality. But the reason why it was so high is because the fan base, while small, is so vocal. Same for Supernatural.
Phineas and Ferb tailored a Family Guy sensibility to a young audience while building a complex mythology with meta references that comment on the repetitive nature of Children's television. It should be an Essential.
Sure. Was apprehensive about adding anything Disney because then we're getting into incredibly murky territory in how to evaluate children's shows when we aren't children. I think I am just going to go with anything that has major crossover appeal to break through like Phineas, like Adventure Time...
If any children's show goes in, it should Spongebob, the show that laid the ground for any children's show to be more than basic.
Amen, children shows shouldn't end up not going in because of their simplicity or basic humor, its is geared more towards the younger audience anyway. Spongebob for Tier 1!
Spongebob has dropped off in quality almost instantly in 2004/2005, becoming a far different show than it was previously, much like the inclusion of The Simpsons, but I will include it.