Upstream Color/Primer
Two indie experimental sci-fi drama films by Shane Carruth. Primer, a time-travel story, is a particular darling of the sci-fi movie community, often billed as one of the most realistic depictions of time travel and its paradoxes. Upstream Color is less overtly sci-fi but is my personal favorite, dealing more with themes of trauma, fate, and psychological intimacy. It's a really beautiful film and is actually often compared to Malick's work in general and Tree of Life in particular. Both are kinda cool in that Carruth not only wrote, directed, and starred in them, but was also responsible for editing, music, and cinematography. Real indie production but of incredible quality.
Valhalla Rising
From Nicolas Winding Refn (probably most famous for Drive and Bronson), the story of a Viking warrior who journeys with a group of Crusaders on a quest for the Holy Land only to end up in lost in pre-contact North America. It's thoroughly grim and hypnotic, filled with feverish vision sequences and scenes of haunting solitude, starring Mads Mikkelsen in a powerful performance of few words. Some might find it more excruciating than entertaining, but it sounds like it might be up your alley.
Samsara
An experimental documentary by Ron Fricke with no narration or overt narrative. More of a meditation on modern life throughout the world, its themes (which admittedly can get a bit heavy-handed at moments) are told through montage, visual poetry, and masterful timelapse photography, all underscored by a fantastic soundtrack. Fricke is one of the pioneers of the use of timelapse in cinema and his previous documentary, Baraka, is much in the same vein and worth checking out. He was also the cinematographer for Koyaanisqatsi and its sequels, the legendary avant-garde documentary trilogy to which this film owes its lineage.
If you're at all interested in the history of experimental cinema, try checking out some of the classic works like Man with a Movie Camera, La Jetée, and Meshes of the Afternoon. Experimental films and video art are one of my great interests, but you definitely need the patience for it or else it can easily become grating or overbearing.
