No again.
There is no best. It's limitless good fights. However, if there was to be a best one that wouldn't even come close to it. And I'm pretty sure an anime isn't aiming to have bland episodes (quite sure of this tbh). If they keep having boring episodes they lose watchers (and since switching the day the anime airs, they've already lost quite a few japanese viewers so I doubt they'd want more people to stop watching).
Here are some great ones:
Hunter x Hunter:
https://www.youtube.com/watch?v=kGap6VdTWS8
https://www.youtube.com/watch?v=gUc6lZrEbCw
One Piece:
Edward Newgate vs Akainu
Naruto:
https://www.youtube.com/watch?v=NdcIyXKEkwQ
and there are so much more.