I agree, Lilo and Stitch is easily my favorite Disney movie. I like Stitch and the other aliens, but I would still love the movie (maybe even love it more) if they weren't in the story and it was just about Nani and Lilo. Like, Nani and Lilo adopt a dog because Nani knows Lilo needs a friend, and Lilo being Lilo picks the most hyper, trouble-making dog she can, and basically the dog would replace Stitch but the story wouldn't be focused on the dog, which gives the story more time to develop Nani, Lilo, and David. Nani and Lilo are such great characters, there was so much thought put into them and their relationship, and even David is a pretty well written character even though he's not in the movie as much.
Treasure Planet is similar, it has characters that are there mainly for comic relief (ugh, I hate B.E.N. so much.. and the fart-noise alien) but the focus is on the father-son relationship between Jim and Silver. Jim's story with his father abandoning him and his mother and his mother being a single parent trying to run a business while raising a troubled kid is very realistic. Silver is so well written and Jim and his mother are such realistic, relatable characters, and visually the movie is stunning and so creative, I fucking love Treasure Planet. The ending is happy but it isn't without it's losses, and I just think Treasure Planet is criminally underappreciated and even though it isn't as great as Lilo and Stitch, it does so much right that it's flaws are forgivable... except for B.E.N.
I like Frozen but I think it could have been so much better. I guess I just think Frozen should have had Elsa as the main character instead of Anna, because Elsa is a much more interesting and deep character that people can relate to. Hans also feels kind of unnecessary, I like him but I think the movie would have been fine without him. I love Olaf, he's so cute and funny while still being able to be emotional, I think him and Elsa are great characters but the rest are a bit bland. Also, I fucking hate that troll song near the end.. that killed the dramatic mood, the rest of the songs are great though.
Lilo and Stitch, Treasure Planet, The Lion King, Mulan, Wreck-it Ralph would probably be my top 5. Tangled, Hercules, The Rescuers, and Sleeping Beauty are favorites as well