Most of the “mainstream” anime. Since 2015, the only very popular anime I really loved instantly is One Punch Man, I guess.
Shingeki no Kyoujin was definitely also good, however, I never hyped the first season as much as other people did. I am actually this person who truly loves SnK since season 2.
Same goes for Hero Academia. Nice anime but the first season is not nearly as good as it’s rated. However, definitely gets better with season 2 and constantly stays at that high level!
And I don’t know if I want to speak about Overlord… the popularity of this anime is truly a mystery to me.