The opening scene sure is great and impressive. The part I most like is the bath scene, where Nala is introduced in the movie. I like the music and atmosphere in that scene, just happy unworried cubbies with nasty plans, and their mothers having a family moment.
The most touching scene is where Mufasa dies during the stampede, I hate the sad feeling it gives me, but when it comes to quality of animating, music, atmosphere....well everything that a movie needs, I have to admit that's the best part of the movie.