Ah, Blue Ruin. One I'm lucky enough to have seen
I have a really narrow definition for thriller
but I called Blue Ruin a thriller, so I guess it must have qualified. The Guest
is another good mention... of the ones I've seen it's far and away the purest of the genre.
Nightcrawler, Prisoners... I liked these even more. I hadn't thought of them as thrillers. Prisoners yes... Nightcrawler, for me no. Snowpiercer I didn't enjoy (outside of some scenes), and it's too many other things for it to meet my made up criteria for being a thriller.
My definition of the genre. No horror, nothing surreal, nothing ghosty or magic, no paranormal stuff, no sci-fi stuff. It's about ordinary
people (not weirdo Jake Gyllenhaal) living their normal lives, and they find themselves in some f'd up situation that isn't any of the above things.