I am sometimes amazed that, when thinking of certain sci-fi TV shows and films, certain scenes will pop into my mind as much for how they were filmed as for what they contained, etc.
Two examples from Babylon 5 come to mind:
1) Sheridan's capture on Mars in the episode "The Face of the Enemy": the way the fight is shown, I am for once all in favor of slo-mo, as it is depicting Sheridan's drugged view of the fight. Interspersed with the slow-motion are flashed inter-cut still photos, that really add something new and interesting visually. Also, the music is paired nicely with the visuals:
2) The 'moment of truth' with Sheridan in 'Severed Dreams": it's a fairly basic camera move to pull off: truck the camera back while simultaneously zooming in with the lens on the subject being filmed. It's been done before and since, but this use of it really helped hit home the weight that had just slammed down on Sheridan's shoulders at that moment. Up to that point, Babylon 5 and its command staff had been walking a fine line with EarthGov, but now they were being targeted by the militant regime just like other breakaway colonies and outposts.
3) A close third is the space battle in movie Serenity when Mal and co. encounter the fleet awaiting them: with the Feds in front of them and Reavers close on their tail, it's a hell of a space battle scene and very memorable:
4) Lastly, an obvious one. 2001: A Space Odyssey. Say what you will about the overall film itself: the story gets trippy and weird at times, but you can't argue with the brilliant visuals, especially anything happening in space. I could post any part of the film really, but I'll just put this one up:
Which sci-fi movie/TV scenes stick in your mind as visually stunning/memorable? Of course, vids or at least photos are welcome in your replies!