I have seen 36/52 and the last 9 in a row without skipping. I will watch the rest one by one whenever I have free time, starting with Fantasia.
Those are the ones I haven't seen yet (in order of release date):
3. Fantasia
6. Saludos Amigos
7. The Three Caballeros
8. Make Mine Music
9. Fun and Fancy Time
10. Melody Time
11. The Adventures of Ichabod and Mr. Toad
23.The Rescuers
24. The Fox and the Hound
25. The Black Cauldron
26. The Great Mouse Detective
27. Oliver and Company
29. The Rescuers Down Under
38. Fantasia 2000
41. Atlantis: the Lost Empire
43. Treasure Planet