I've never been good at picking single favorites of anything. However, I can only think of five movies I saw and liked as a kid. I can't really explain what I had against movies as a kid, especially when I look at the five movies I liked and consider some of the other movies I saw and was neutral towards. (I sat through Gandhi and Amadeus, but couldn't deal with Mr. Mom, ET or The Empire Strikes Back? Alrighty then.)
I only saw three of the five movies I liked in the theater, and those three are the only actual kids' movies on the list, so I'll start with those three.
Robin Hood (Disney's animated version), which was rereleased to the theaters the year I turned 8,
The Secret of NIMH, and
The Great Mouse Detective. Heh, I'm now not even sure that last one counts, since I was twelve when it came out, but I suppose anything I liked before I was a teenager counts. Do I still like them? Yes. I own them all on DVD. Can I explain why The Secret of NIMH wasn't too dark but ET and The Empire Strikes Back were? No.
The other two movies I saw on TV, some time after their theatrical releases.
Foul Play, the only Chevy Chase movie I like, and
What's Up Doc? which may be the last screwball comedy ever made (And is two years older than I am. Weird.). Do I still like them? Yes. I own them on VHS. (I haven't done a great job on updating my movie collection to DVD.) Why were those two comedies great and Mr. Mom awful? I prefer adventure comedy to real-life comedy and I don't like movies about people making fools of themselves. Why don't the antics in What's Up Doc? qualify? Maybe because I never feel like we're supposed to be laughing at the main characters, maybe because the characters never seem embarassed, I'm not sure.
Now that I think about it, the only real difference in my taste for movies is that I like a lot of adventure movies that were (or would have been) too scary for me as a kid. The Empire Strikes Back, for example. In fact, adventure movies are the only movies I didn't like as a kid and now do. Most comedy still creeps me out. Oh, and I don't watch historical dramas with my parents any more. They're just not my thing.