Some of my favorites in no particular order:
Lady and the Tramp
A classic Dog movie.
The most classic dog movie. I love everything about it.
The Little Mermaid
I love the songs.
Atlantis: The Lost Empire
An underrated gem. An Indiana Jones-style animated movie that doesn't get as much attention as it deserves. Can't understand the bad ratings.
So fun and great. A gem that doesn't get much attention now days either.
Sequels: (they aren't really that bad)
Lady and the Tramp 2: Scamp's Adventure
A movie that improves upon the original. It was fun and I liked it almost as much as the original.
101 Dalmatians 2: Patch's London Adventure
A movie that stares Patch as the main character, and I have to say, they did a good job with this sequel.
Ok, I might get a lot of criticism for this, but I feel people hate this movie way more then they really should. To be honest, this spy esthetic works great for me. And they did a great job developing Mater's character. I don't care what people say. I love this movie.
Don't need to say why
A great movie that brings the Disney magic back.
Whoever had this idea was a genius. I love it.
Some of those sequels are truly bad, but most are from decent to good in my opinion.