If you liked
Sword Art Online
|
...then you might like
Darling in the FranXX
|
Both provide a more simplistic sense of enjoyment with romantic elements and don't require complex thinking. Therefore I would ignore recommendations saying you should watch Neon Genesis Evangelion, if you liked Darling in the FranXX: The similarities between them are solely superficial, they don't feel similar, SAO and DitF on the other hand do. When you're watching an anime, superficial factors just don't play a big role.
If you liked
Kotonoha no Niwa
|
...then you might like
Kimi no Na wa.
|
Two Shinkai movies, while Kotonoha no Niwa is more realistic, Kimi no Na wa is more entertaining. Both give you the Shinkai-feeling.
If you liked
K-On!
|
...then you might like
Tamako Market
|
Both are lighthearted comedy with a unique way of using music. They also share the same studio and director.
If you liked
Sword Art Online
|
...then you might like
Beatless
|
If you're just looking for simple entertainment with some romance in it.
If you liked
Nagato Yuki-chan no Shoushitsu
|
...then you might like
Shingeki! Kyojin Chuugakkou
|
Both are comedic Spin-offs from popular Animes, which gain their strenght from their references to the main shows. They are both good at what they are doing.
If you liked
Suzumiya Haruhi no Yuuutsu
|
...then you might like
Charlotte
|
The overall tone and the supernatural aspects are kind of similar, even though Charlotte is a bit more serious.