Answer
If your idea of a sci fi movie is just chasing monsters in space or being chased by monsters on earth and running screaming, our ideas are different. though some really nice ones have been of that nature. some of my favorites, and many of them are classics and fare from new, are as follows:
2001;a space odyssey
the star wars movies
close encounters of the third kind
alien....and some of it's sequels
et
jurassic park
independence day
men in black
matrix
a clockwork orange
soylent green
waterworld
i robot
the terminator and sequels
a boy and his dog
mad max...only the original
the omega man
the andromeda strain
i am legend
total recall
the manchurian candidate
blade runner
kids of men
twelve monkeys
spider man and sequels
iron man
and....only because i got hooked on them because a nice friend played mr. grey in the original, resident evil, which really is not all that nice...lol