There's a trope of heroes walking towards the camera in slow motion, shoulder-to-shoulder.
What was the first movie where this kind of shot was used?
An early and highly influential example must be the Droogs' walk in slow-motion side by side toward the camera (set to Alex's voiceover and a Rossini piece) in Kubrick's A Clockwork Orange (1971). Ironically, our 'heroes' are a gang of sociopaths and a vicious slow-motion fight breaks out midscene, which is juxtaposed with the classical music. This will later echo in the Reservoir Dogs title sequence, depicting another uniformly-dressed gang of criminals in a slo-mo walk set to music, which perhaps hints at their fate. Here's the Clockwork Orange scene (starting at 0:28):