It's hard to believe now, but Marvel lagged DC in the adaptation game until the 21st century. Yes, the classic Spider-Man, Fantastic Four, and Iron Man series were massive hits in the 60s, but DC dominated the small screen. Kids might have loved singing the Spider-Man theme, but everyone was dancing the Batusi. And with the arrival of the Superman movie franchise in the 70s, DC only widened the gap. Although the same couldn't be said about sales on the comic front, Marvel couldn't compete with DC in the realm of multimedia.
By the time the 80s rolled around, X-Men was Marvel's hottest book and paved the way for the mutant sales supremacy that still exists today. Before the success of their 90s adaptation, Marvel attempted to make the X-Men a household name in the 80s. In the video linked above, I present to you the only episode ever produced of the failed 1980s cartoon X-Men: Pryde of the X-Men, which predates the successful X-Men: The Animated Series by several years. Also, there's a creepy ad at the beginning where Spider-Man tells you to vote. So, yeah, there's that.