For anime...
Gintama definitely. What a perfect adaptation of the manga, but also has its own identity. So well done.
I also really like Slayers. But. Nobody knows that series because it's an old 90s one lost to obscurity.
Soul Eater had a lot going for it, right up until they butchered the last half of it and went off book from the manga. I really hope it gets a reboot.
Ghost in the Shell. (All of them!)
Appleseed, Battle Angel Alita, Akira, and Mob Psycho 100 are all good runners up.
I adore One Piece, but the anime has lost its luster for me, so I stick with the manga only there.