I think when looking at the Disney sequels, the <I>first</I> thing that should be taken into account is the animation. Does it meet the right standards that it could sit alongside other Disney content and not look cheap or out of place.
Then the success of the film, artistically, is down to the story. So in terms of the Disney sequels, I would place an ability to fit in to 80 years of animation content above how the story came out.
For these reasons, and TV origins aside, I can't take anything like the Aladdin follow-ups or those others "seriously" as anything other than TV movies. Fine for what they are, but not much else.
Story-wise, once you've evaluated the technical aspects, you can drop a few more out of the list. Arguably, and as much as I enjoyed certain aspects of these two films, I think anything called "II" or "2" should be a follow-up, a continuation, so I wouldn't put Bambi II or Tarzan II in any line-up of "successful" sequels.
Ultimately, a Disney follow up being exhibited as a "Disney Movie" should: 1) meet the basic standards of Disney animation (and let's be honest and come right out and say that Disney animation has had a lot of looks over the years and not all of them were pretty or indeed particularly well animated), and 2) create a compelling continuation storyline.
Under these "rules", I'd say the only sequels worth considering (and I'm neither endorsing or dismissing here) are:
Lion King II: Simba’s Pride
An Extremely Goofy Movie
Lady And The Tramp II: Scamp’s Adventure
Peter Pan: Return To NeverLand
101 Dalmatians II: Patch’s London Adventure
The Jungle Book 2
Mulan II
Lilo And Stitch 2: Stitch Has A Glitch
Cinderella III: A Twist In Time
So it's actually quite a small list of artistically and creatively successful pieces. To this list, I would add several others, produced by the Disney TV studio but in formats true to their original nature:
DuckTales The Movie: Treasure Of The Lost Lamp
A Goofy Movie
The Tigger Movie (the only true theatrical Pooh follow up)
Doug’s 1st Movie
Recess: School’s Out
Teacher’s Pet: The Movie
Mickey, Donald And Goofy: The Three Musketeers
For good measure, the "inter-quel" The Lion King 1½ should be included for being something quite special - a rare "what if?" attempt to subvert Disney on nothing less than their most successful feature film.
That's my criteria, anyhoo!
