1.) Avengers Earth's Mightiest Heroes '10 - great animation, scripting, stories, everything. I loved the guest stars and the feeling that these weren't Avengers stories, but Marvel Universe stories featuring the Avengers.
2.) Spider-Man & his Amazing Friends - great animation for its time and I looked forward to different guest stars week after week.
3.) The Incredible Hulk '82 - more great animation for its time.
4.) Spider-Man '67
5.) FF '66
Honorable mention: The Marvel Power Hour, I believe it was called. Hulk, Sub-Mariner, Thor, Captain America & Iron Man stories. Crudely made but this was my early intro to many of these characters on TV.