Not sure if you have watched these:
Saute ma ville (1968, Chantal Akerman)
Origins of the 21st Century (2000, JLG)
Adebar (1957, Peter Kubelka)
Aguaespejo granadino (1955, José Val del Omar)
Wavelength (1967, Michael Snow)
The End (1953, Christopher Maclaine)
What The Water Said, nos. 4-6 (David Gatten) this probably my favorite short film
Song and Solitude (2007, Nathaniel Dorsky)
Isiah Medina had cool short films in his vimeo channel, not sure if he hasn't deleted them yet