Fantasia is one of my favorite movies, but I've always felt the Pastoral/Beethoven segment drags and is comparatively ordinary compared to the rest of the film. It should have been released as a Silly Symphony on its own and replaced with the deleted "Clair de Lune" segment.
The Toccata segment is a masterwork of abstract animation. The Nutcracker is one of the most beautiful sequences ever animated. The Sorcerer's Apprentice brings Mickey from routine to the sublime. The Rite of Spring has all the great naturalistic animation, plus a surprising accuracy to natural history. Dances of the Hours is hilarious. Night on Bald Mountain is terrifying, only to be overpowered by the beautiful Ave Maria coda.
The Pastoral doesn't really offer anything special besides pretty animation and the mythology.