

The original “Mobile Suit Gundam” trilogy (79 up to ZZ), “SDF Macross” and “Macross: DYRL” come to mind. It only makes sense, since a good space opera requires epic soundtrack. And those are the really big ones. Evangelion also has a very nice opening theme.
Currently re-watching Miss Kobayashi’s Dragon Maid season 2 (I probably watch the whole series once per year since it was launched); Recently finished re-watching the holy Gundam trilogy (Mobile Suit Gundam, Z and ZZ); Getting ready to re-watch SDF Macross and Macross: DYRL; Waiting impatiently for the next season of Spy x Family; Happy to have discovered Natsume’s Book of Friends.
Needless to say, all of the above are must watch.