Are you specifically looking for anime with a gorgeous retro-futuristic aesthetic, like I was talking about? If so, this channel will help you explore some you might be interested in.

https://youtube.com/@hanahakiblank

OG Dragon Ball, and Dragon Ball Z.

Well you didn’t ask me nor did you provide parameters other than age so here’s a list (mostly in the order I remember them, varying genres and ages, all pre-2010 many pre-2000):

Cowboy Bebop
Samurai Champloo
Ruroni Kenshin
Devilman (OG 1976, NOT reboot)
Mazinger Z
Galazy Express 999
Golden Boy
Trigun
Cat Soup (movie)
Berserk
Big O
Samurai Pizza Cats
Bobobo-Bo Bo-Bobo
Shin Chan
FLCL
Dragon Ball (OG, Z, ignore GT)
Fist of the North Star
Yu Yu Hakusho
Inuyasha
Golgo 13
Ghost Stories
Hare and Guu
Lupin III
Sailor Moon

And I’m sure I’m forgetting some.