My first four come readily to mind and in order seen they are: 2001: A Space Odessy, Star Wars, Blade Runner, and The Matrix. The fifth is another story though and these are my contenders (again in order seen): District 9, Moon, Her, Ex Machina and Children of Men. I've seen each of these but once and will be watching each again to decide. I actually watched District 9 again a few nights ago and it's not going to be my fifth, but it's an excellent film. I'm thinking five will be either Children of Men or Moon.