Gintama, hands down. Gintoki is my fav manga/anime protagonist of all time. The series has so much humor but it also has can break your heart. I have legit bawled my eyes out during some of the episodes. The art gets better overtime and it has both stand alone stories and massive arcs.
Also in the running for favorites are:
My Hero Academia – my almost co-fav anime/manga and currently the best take on superheroes. Marvel and DC could learn a thing or two from the mangaka.
Katekyo Hitman Reborn (older and complete)
One Piece (not caught up)
Fullmetal Alchemist (both series, though Brotherhood follows the manga so it’s better imo)
Hunter x Hunter
Kenichi the Mightiest Disciple
Seven Deadly Sins
Ahhh I could go on so I will stop there but there are tons of anime that I simply adore.
My favorite anime has a story. When I was in High School, I was bumming around one Saturday when I stumbled on a TV show on UPN called Teknoman. They were airing the first 6 episodes from what I remember. I was intrigued.
It was later that I learned it was anime. Later still that I learned what it REALLY was called, Uchu no Kishi Tekkaman Blade! Not the greatest anime in the world, but I consider it my first, and therefore, special.
I had watched Robotech, Voltron, G-Force and Speed Racer before… But this is the anime that I started watching with as an anime fan. Shortly after that, it was Dragon Ball, Robotech on Toonami (also known as when learned to stop caring and love Macross) and so on.