The little known "series" that came out in 1989, and lasted for only a single episode. More comic-bookish and stylized than the series we would all watch several years later, it had a more diverse team as well. Cyclops, Storm, and Wolverine are standard fare for X-Men cartoons, but Nightcrawler, Colossus, Shadowcat, and the Dazzler round out this team.
The only episode ever made, Pryde of the X-Men, focused on Kitty Pryde, the Shadowcat, arriving at the X-Mansion and getting a "crash course" on being an X-Man when Magneto and Juggernaught literally crash through the front door. We get a very nice pairing off as the X-Men storm Avalon and go up against the Brotherhood of Evil Mutants (Colossus against Juggernaught, Wolverine against Toad, Cyclops against White Queen, etc). In the end, the X-Men triumph, they save the world, and Kitty rescues Lockheed from Magneto.
Its a shame this one didn't take off, it would have been fun. Despite the fact they gave Wolverine an AUSTRALIAN accent instead of a Canadian one.