It Came From Beneath the Sea

This is an enjoyable monster movie from the 50's that pits a giant octopus (awakened from the depths of the ocean by atomic explosions) against a nuclear submarmine, fishing boats, the Oregon coast, and finally the city of San Francisco. Special effects guru, Ray Harryhausen animated the beast. It worth it just to see the octopus pull apart the Golden Gate Bridge. Science fiction, the atomic age, and monsters were all just made for each other.