The Lion King
This was the bookend to Disney's latter-day renaissance that began with The Little Mermaid. The music, story (a reworking of Hamlet), and the characters are flat-out fantastic, and they all helped the film become the highest-grossing traditionally animated (two-dimensional) film of all time. It's pure, powerful entertainment from start to finish, thanks in large part to numbers like "Circle of Life" and "Hakuna Matata."