Days of Future Piff
All Star
There's a TVtropes term called "Growing the Beard", which is basically when a series/show/movie/etc. starts getting really good. 
(Named after Star Trek: TNG because of the fan consensus that the series really took off right around the time Riker grew a beard. It's like the opposite of jumping the shark.
Some examples that I think of:
The Empire Strikes Back (Even though the original was
)
One Piece- The walk to Arlong Park
Giant Sized X-men #1
Video game example:
Super Metroid
When did your favorite series pop off and start getting super dope?
(Named after Star Trek: TNG because of the fan consensus that the series really took off right around the time Riker grew a beard. It's like the opposite of jumping the shark.
Some examples that I think of:
The Empire Strikes Back (Even though the original was
)
One Piece- The walk to Arlong Park
Giant Sized X-men #1
Video game example:
Super Metroid
When did your favorite series pop off and start getting super dope?