He died prematurely and has only a few films in his repertoire. I suggest seeing them all if you can do it.
If not, do watch Perfect Blue as well. 😊
'5 cm' is Shinkai's best work IMO. He uses a lot of montage arbitrarily in all of his films, but it worked in this case.
Dunno about rewatching though 🙅, if you can manage the time, sure.