Forgot about the Mad Max movies, loved those too, and I would have listed Terminator myself but I didn't see it until many years later so I can't really consider it a "childhood" film even though I was a kid when it came out and although I love it and think it's a classic.
One that I never really cared for even though it's considered a cult classic is Blade Runner. I love Harrison Ford and Ridley Scott but this movie just never did anything for me.