It’s hard to choose a favorite, but one that comes to mind is the Star Trek Enterprise episode “Carbon Creek” where some Vulcans crash land on Earth in the 1950’s (before first contact) and introduce humanity to velcro.

THIS is the kind of action I was hopeful for. I haven’t had a reddit account in nearly two years out of principle, and it feels great to be able to geek out/interact with other star trek nerds online.