Plot
Airing in 1991, this was the first ongoing X-Men cartoon, although they had appeared earlier in a number of guest appearances in Spider-Man and His Amazing Friends and in a pilot episode in the mid-eighties. It ran for 77 episodes. This version of the team (and the universe they are in) bears strong resemblance to the mainstream Marvel one, with many storylines being variations of ones from the comics. Basically who does what when and to whom might change, but the characters are generally very true to the comics. One of the biggest differences is the character of Morph. This was a renamed Changeling, whom in the mainstream universe died while doubling for Professor X. Morph has become the second cartoon character (after Firestar from Spider-Man and His Amazing Friends) to make the transition back into Marvel Comics proper, appearing first in the alternate universe Age of Apocalypse storyline, then popping up in Exiles. Perhaps unsurprisingly for a show which relied so much on the mythos of the original comic, there were very few brand new characters invented. Other than Morph, I can only think of one.
IMDB
http://www.imdb.com/title/tt0103584/
Season 5
The Phalanx Covenant: Part 1
S5, Ep1
Sep. 7, 1996
The Phalanx Covenant: Part 1
The Phalanx Covenant: Part 2
S5, Ep2
Sep. 7, 1996
The Phalanx Covenant: Part 2
A Deal with the Devil
S5, Ep3
Sep. 14, 1996
A Deal with the Devil
No Mutant Is an Island
S5, Ep4
Sep. 21, 1996
No Mutant Is an Island
Longshot
S5, Ep5
Oct. 5, 1996
Longshot
Bloodlines
S5, Ep6
Aug. 28, 1996
Bloodlines
Nightcrawler finally meets the mother who gave him up... Mystique.
Storm Front: Part 1
S5, Ep7
Nov. 2, 1996
Storm Front: Part 1
Storm Front: Part 2
S5, Ep8
Nov. 9, 1996
Storm Front: Part 2
Jubilee's Fairy Tale Theater
S5, Ep9
Nov. 16, 1996
Jubilee's Fairy Tale Theater
Jubilee and a group of children are trapped by a cave-in in the caverns underneath the Xaviar Mansion, she tells a fairy tale to kill time while they wait to be rescued.
Old Soldiers
S5, Ep11
Feb. 22, 1997
Old Soldiers
While visiting the grave of a friend in an Army Cemetary in France, Wolverine remembers a mission he did for him, while battling the Nazis and Red Skull with none other than Captain America on his side.
Graduation Day
S5, Ep14
Sep. 20, 1997
Graduation Day
On the verge of Magneto's final stand against humans, the X-Men request him to save a dying Professor X. What choice will he make