Not necessarily favourites, just stuff I used to like a lot. I say used to because I don't know whether I would anymore since my enjoyment level of things isn't like it once was. Sometimes this stuff is just a reminder of before my anhedonia got to the level it is now.
Anyhow, no particular order and off the top of my head -
Legend of the Galactic Heroes
Monster
Revolutionary Girl Utena
Haibane Renmei, Serial Experiments Lain, Texhnolyze. I grouped them together because of sharing staff.
The Tatami Galaxy (I haven't really seen anything I haven't liked from Yuasa though tbh. His style alone is visually interesting).
Princess Tutu
Rose of Versailles (Osamu Dezaki is another excellent director imo)
WMT (World Masterpiece Theatre) series -
https://en.wikipedia.org/wiki/World_Masterpiece_Theater
Mushishi
Seirei no Morbito and The Twelve Kingdoms I found likeable for more fantasy orientated stuff.
Kaiji
Oyasumi Punpun (Goodnight Punpun) and generally other Asano works are up there for me when it comes to manga.