Pretty classical question, curious to see what you all think.
For me, it’s Pacific Rim. It is mostly about giant robots fighting huge monsters, but the the psychological treatment of the characters is more refined than someone would expect for this kind of movies.
spoiler
And the intro is very poignant scene, again, not something you would expect in this kind of movies.
Gattaca (1997) - Sure it has a relatively high IMDB score but no one I know has seen it and I always recommend it when I can.