Origin: Donald Sutherland, in 1978's remake of Invasion of the Body Snatchers
Actual meaning behind the meme: Invasion of the Body Snatchers is one of the few truly great remakes ever produced by Hollywood - and not only is this a great moment from the film, it's THE moment that solidifies it as something dark and powerfully unique. Donald Sutherland has watched all of his friends and loved ones be taken by the pod people and lost to him - then at the very end of the film, he runs into someone who has managed to escape the alien menace. She approaches him with joy and excitement and DONALD SUTHERLAND STARTS TO POINT AND SCREECH - meaning even he, our last hope for humanity, has too been turned. It's a powerful and dark note to end the film on, and way better than "Donald Sutherland accusing hipsters of being lame" or whatever stupid meme thing that is now.
To put it into modern context - imagine if the last moments of The Mist (which are truly fucked up beyond regard) were turned into a meme about being sad you sent a text without enough emojis or something.
Origin: Patrick Stewart, in Star Trek: TNG's episode, Menage A Troi
Actual meaning behind the meme: In one of the goofier moments from TNG (which doesn't narrow this down at all, really), Picard (aka Patrick Stewart) is trying to negotiate for a crew member's mom's return from a lovelorn alien who's kidnapped her. When she comes on the videoscreen, she pretends that she and Picard are former lovers, and tries to nudge Picard into playing the part of a spurned ex-boyfriend. And so Picard does, reciting Shakespearean sonnets to declare his undying love for Lwaxana Troi (ugh, the names on this show). So no, it's not a Starfleet captain saying "Come on, old school Family Guy is WAYYY better" or whatever - it's something infinitely better: PATRICK STEWART ROCKING SHAKESPEARE IN SPACE TO TRICK ALIENS.
The specific frame is even the classic line "Shall I compare thee to a summer's day?" And no, Jean-Luc, you probably shouldn't. Ugh, Lwaxana, am I right? Also, ugh, we were SO CLOSE to getting rid of Wesley here. Really, if not for this great scene from ol P-Stew, this episode wouldn't have been worth nothin'. Why do you want to take this from me, memes?
Origin: Nicolas Cage in an insane scene from Vampire's Kiss
Actual meaning behind the meme: He's not saying "You don't say!" Nicolas Cage doesn't utter anything REMOTELY LIKE "You don't say!" in this entire scene. But that's fine - because whatever the hell IS going on in the scene is infinitely better.
Some context - Vampire's Kiss is an objectively terrible film. Nicolas Cage is straight-up out of his mind the entire time and virtually none of the plot - sort've a proto-American Psycho where Cage is a high-powered business guy who thinks he's becoming a vampire - makes a goddamn lick of sense. The Washington Post declared it and Cage "incoherently bad." And this scene is a perfect summary of the film. Cage is ranting to a lowly secretary about the real shitty job he's gonna make her do - and how he's going to revel in making her suffer through the most menial, painful task possible. His eyes bug out and and he chews the scenery like only Nicolas Cage can. Really, it's one of the most watchable bad performances ever, and so much more than that meme would lead you to believe.