I don't think Lilo & Stitch is over-rated.
And Bedknobs and Broomsticks is awesome! Angela Lansbury sings and fights Nazis with walking Middle Ages armor! How cool is that? Also, it's just so much fun, and I love those songs! And Eglantine and Professor Brown made such a good pair. Oh, I love that film (more than Mary Poppins, I admit, much as I love Mary Poppins.)
Under-rated
The Rescuers Down Under is definitely under-rated, yeah. It's my favorite Disney movie (after Lilo & Stitch), and has to be in my top ten movies overall. But I just...love it. It's a little gem, too often forgotten...partly, I feel, because it was sandwiched between The Little Mermaid and Beauty and the Beast. And it's just smaller in nature than the big ones that followed it (Beauty, Aladdin, The Lion King).
But it works so well on so many levels. It has romance (which was so sweet), and adventure (Disney's best animated adventure, I feel; and they often stumble on their animated adventures). Had action, too, and humor. A well-rounded stable of emotions...and it moved with such an ease and comfort. They juggles, like, what...three different plot-lines at some points (Bernard and Bianca and later Jake, Cody and McLeach, and then Wilbur and his exploits), and yet it never dropped the ball. It balanced them all, and they all came back together.
That and the fact...that the animation is simply gorgeous, crisp, bright, colorful, warm...the Australian Outback (especially when Bernard and Bianca are sitting on that log over the water, waiting for Jake to return), and the flight (through the clouds, off the waterfall, and the end flight up into the stars; so lovely). And the score was noble and regal and sweet, and so on...and the voice cast was excellent, from Bob Newhart and Eva Gabor, first and foremost, and also George C. Scott and John Candy. And...yeah, cause I could go on. I do love this film, and feel it's too often forgotten or brushed aside. And while I do love the original, and without the original Rescuers, RDU wouldn't exist...but I just have more an attachment to this one, and think it's better. (But that's just me.)
So under-rated, yes.
And under-rated, also, Brother Bear. The critics all conspired in some sort of...conspiracy. They had it out for this film or something...before it opened. I think that they were spoiled with the likes of (though I like them, too, just don't love them) Spirited Away and Finding Nemo (which, in some ways, are aimed at adults, as well as kids; they work on two levels). Not to say that Brother Bear doesn't, but it's not...that type of film. It wasn't critical fodder, I guess.
But it was a warm film that was lush...and had good messages, and not only was the animation lovely to look at, but the lead characters (Kenai and Koda, and the supporting moose) were well-realized, and the relationships were touching. And there was action, drama, humor. I understand it's not Disney's best effort, or most original, but I honestly...fell in love with it. It was a really nice film, and I enjoyed it, and I think that...it is under-rated. I can't wait for the DVD!
Also under-rated: Oliver & Company. Though, more than a lot of other Disney films, it feels really dated (it is SO an 80's film, and you can tell that even if you didn't know when it was released). It doesn't have a timless quality like some other Disney released, but the songs...really are fun (especially the first two, the one about Oliver...yeah, that narrows it down. lol. The opening song. And then the "Why Should I Worry?" And I have to love "Perfect Isn't Easy.") And, yeah, the animation looks grittier...and not as pretty, I guess, but it's set on the streets of New York City, so...and didn't I hear (on one of the extras on the DVD) that the backgrounds and characters were animated with the same...technique, or something.
I would also say The Emperor's New Groove. It was really quite funny. Zany. But with heart, too. Which seems to be the style that Home on the Range will have...so I wonder how that will turn out.
Oh, oh. Fantasia 2000. As with the Rescuers vs. RDU thing, I like the sequel better...in this instance, also. Too often, this one is compared to the original (and that's only natural). But the animation is gorgeous, all the different styles, and the accompanying music. I could watch many of those segments over and over again. And maybe the fact that, at least for the bulk of its run, it was only on IMAX...makes people not take it as seriously? But I don't think a full-blown regular theatrical release...would've been as successful (and I only wish I had been able to see it on the IMAX!) But I think Fantasia 2000 is often dismissed...as being too lightweight, or something. But I think...under-rated.
Over-rated
If I had to choose (and I still do like these films, mind), I would have to say things like The Great Mouse Detective and The Fox and the Hound. I would say The Jungle Book, too, but I haven't seen it in a while.
And the Pixar films. While I like them (and, I'll admit, I do have a bias against computer animation that I'm finding hard to shake), I do think that...people are too eager to declare each Pixar film "the best thing since sliced bread," or at least, "the best one yet," and they do that with every single one. And while I agree Pixar is quite impressive, and I liked Nemo (and will be rooting for it at the Oscars, especially for score), I don't think it's the best animated film ever (as its box office and public approval and critical raves would seem to indicate).
I can't belive that many people think this was a good sequal! It was short, boring, and they replaced the Ticking Crocodile with a Purple Octopus!!!! 
