Name one anime that had one amazing season

[Elvis]

Name one anime that was mostly mediocre, but had one season that was amazing, better than all the other seasons.

 

[DarkAngel]

can't think of anything lol
sword art online may be. i don't like the second season and i haven't followed it after that

 

[Star_Of_Hope]

Probably Kaytekyo Hitman Reborn.
It started getting better after a very long time which made me continue watching it.