Its not that easy (atleast with thriller, but more ambigous genre to qualify movies to), most should be obvious, but of top of my head would say (sci fi)
Blade runner, Close encounters of the third kind, Brazil, Alien,
Planet of the apes, Akira, Ghost in the shell, Cowboy bebop (last three are anime, but recommended still)
Serenity, War Games,
Terminator 2, Cubic (or Equilibirium)
Twelve monkeys, Wall-E, A clockwork orange,
Donnie Darko, Dark City,
Inception, Back to the future, Children of men,
The man from earth (should count as a sci fi me thinks?).
I could go on, prolly forgot alot, like E.T and most of the older sci fi flicks. And oh, anything based on Phillip K. Dicks work