Awesome Music: Belle's song, "Stories". It's hard not to be inspired by her determination to help him be a better person, especially as it ties back to the Romeo and Juliet scene from "Human Again". ("We will slay the dragons that still follow him around/And he'll smile, yes, he'll smile/As his dreams leave the ground...") It's also one of the best deliveries of the "Reading Is Cool" Aesop extant, and the animation is unique and memorable thanks to the Art Shift. There's a reason it was included in the opening titles overture and became the film's Leitmotif, even more than "As Long as There's Christmas".
Everything about him is creepy. From his ability to casually destroy the castle, to the fact that he will die if his bolts come loose from the wall, to... everything about him.
His human form (seen in a flashback) is creepy as well.
As if the flashback scene where we get to see the prince get turned into the Beast isn't bad enough, the Enchantress's true form manages to be both a stunningly beautiful and terrifying bit of animation (her cold face and empty eyes are the kickers), only aided by Kath Soucie's wonderful voice work. The idea of actually seeing the Prince physically transform into the Beast was one of the late Howard Ashman's original ideas for the original film, which was rejected. Perhaps it would've been better not to reinstate that detail even if Howard had originally wanted it (unlike the reinsertion of the song "Human Again").