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The first timeline is the Marvel Productions Universe consisting of 3 shows starting with "Spider-Man (1981)" and ending with "The Incredible Hulk (1982)".
The main Marvel Animated Universe started with "Iron Man: The Animated Series" and ended with "Avengers: United They Stand". "Spider-Man Unlimited" is the sequel to "Spider-Man: The Animated Series" and is loosely connected to this universe. "X-Men: Pryde of the X-Men" is a stand-alone, unrelated prequel to "X-Men: The Animated Series". "Solarman" is similar as both took place before the official MAU but are failed, stand-alone pilots.
The now current and most recent animated series timeline is the Marvel Animation Universe consisting of "Ultimate Spider-Man" to "Guardians of the Galaxy" and two movies. "Marvel's Spider-Man" is a reboot and replacement for the previous series, "Ultimate Spider-Man", coinciding with the "Spider-Man: Homecoming" movie.
Another universe is the Marvel Anime Universe consisting of "Wolverine", "Iron Man", "X-Men", and "Blade" and three stand-alone movies.
The next universe is comprised of "Wolverine and the X-Men" to "The Avengers: Earth's Mightiest Heroes".
"X-Men: Evolution" is a stand-alone reboot of all previous "X-Men" shows. "Spider-Man: The New Animated Series" was inspired by the "Ultimate Spider-Man" comic line. Though, after the success of the first "Spider-Man (Toby McGuire)" film, the show was reworked to follow that continuity. Subsequent series "The Spectacular Spider-Man" and "Ultimate Spider-Man" would become progressively more influenced by the "Ultimate Spider-Man" comic line. Regardless, "Spider-Man: The New Animated Series" and "The Spectacular Spider-Man" are stand-alones, while "Ultimate Spider-Man" started the current universe though it's been reworked as "Marvel's Spider-Man". Similarly, "Fantastic Four: World's Greatest Heroes" is also stand-alone and was made as a response to the first "Fantastic Four" film.
The "Ultimate Avengers" movie and "Ultimate Avengers II" series are the next universe mark a separate universe classified as being one or joined under one universe to "Iron Man and Captain America: Heroes United". The remaining movies can be put together into a universe or combined with everything previously to "Ultimate Avengers" to create one whole stand-alone movie universe or two separate stand-alone movie universes. Regardless, these remaining movies are majority stand-alones that build on the lore of characters and team-ups.