The Adventures of Prince Achmed is the earliest surviving animated feature film in existence. It was made by German animator and director Lotte Reiniger in 1926.
Fantastic Planet - a psychedelic trip to an alienating planet inhabited by blue Draags, keeping Oms as pets. But the Oms plan to escape from this fate.
The Secret of Kells, or the secret of the book of Kells, is uncovered through the adventures of young Brendan, his cat Pangur Bán and the mysterious Aisling.
Two rides on the Galactic Express. Two films, one based on Kenji Miyazawa's book, and one with strong ties to it. Both animation, both from Japan. One from 1985, one from 2014.
The Tale of the Princess Kaguya (2013) tells the oldest recorded tale in Japanese history. Directed by Isao Takahata, known for Grave of the Fireflies. Simple 2D animation, but one of the most beautiful animated films ever created.
Tokyo Godfathers stars three homeless people who find a baby left behind. They set out on a crazy search for its parents during the cold Christmas days.
Angel's Egg is the strangest film I have seen to date. It comes with a beautiful soundtrack and eerie scenery. A masterpiece in the category of conceptual art films.