X-Men: The Animated Series aired from 1992-1997 on Fox Kids and ran for 5 seasons. The series adapted many classic X-Men stories, ranging from the Dark Phoenix Saga to Age of Apocalypse, and starred a core team of X-Men mostly based on the team featured in the then recent Claremont/Lee X-Men book (Beast, Cyclops, Gambit, Jean Grey, Jubilee, Professor X, Rogue, Storm, Wolverine) and the series also featured recurring appearances from other X-Men members (most notably sizeable appearances by Colossus, Morph and Nightcrawler). Other X-Men teams, such as X-Factor, also appeared multiple times in the show. Interestingly, despite lasting 5 seasons and featuring the majority of iconic X-Men characters, Kitty Pryde never appeared in the show.
Seasons 3 and 4 were mostly aired out of order causing inconsistencies and continuity problems between episodes. The series was originally intended to finish with Season 4 but 8 more episodes were ordered at the last minute resulting in the fifth season which featured animation by a different studio and many voice actors being replaced.