Depends on what sort of genres you like, or how obscure or left-field your tastes. The following are a bunch of films on Netflix that I've seen over the last year or so. Not completely left of field, but not the sort of films that got a lot of play in multiplexes (the kind of films you used to have to go to the Screen to see) .
Son of Saul - Grim but brilliant story of man trying to give his son a proper burial in a concentration camp. Won the best foreign language oscar in 2016.
Bone Tomahawk - A western with a large dollop of horror mixed in
It Happened One Night - Okay this is pretty famous, but if you haven't seen it you should. The first great screwball comedy, it was directed by Frank Capra and starred Clark Gable (whose performance here was the basis for Bugs Bunny).
The Nice Guys - Fun Shane Black film, good dialogue, funny and of course has a voice over and a scene set at Christmas. Look out for the Rockford Files reference
Under The Skin - An odd but excellent mood piece, were Scarlett Johansson plays an alien who goes around Scotland in a Van picking up men in order to kill/consume them. Most of the men in the film weren't actors but randomers on the street who Johansson picked up, they then signed release clauses to allow the director to use their footage. Great electronic foreboding score.
The Diary of a Teenage Girl - Coming of age tale of a teenage girl in mid-seventies San Francisco.
The Neon Demon - More of a mood piece than anything plot driven (the plot is a rather slight morality tale about the dangers of the fashion industry). Very stylish, but has a couple of scenes which are quite visceral. Fantastic electronic score.
Sicario - Good thriller set against the backdrop of the war on drugs. Has a couple of really great high tension scenes.
Ex Machina - Superior Sci-Fi, as a man participates in an experiment to see if an android has achieved actual consciousness. At times quite creepy.