Pretty much everything from Weird Al.

Blazing Saddles. It killed the western genre for a long time because of how well it parodied them

Hot Fuzz is the best buddy cop movie I've ever seen.

For my wife Spaceballs is the original and Star Wars is the spoof.

But more seriously, too many people didn't register that Scream was a parody. That way it managed to surpass older slashers.

Galaxy Quest!

Airplane parodying the airliner movies like Zero Hour

Dr Strangelove parodying atomic terror movies like Fail Safe

Naked Gun.

Austin Powers.

Team America: World Police

Weird Al's White And Nerdy, so much better than Ridin Dirty.

r/TheDonald. If I remember right, it started as a meme sub before he actually ran, then it was overtaken by actual supporters.

The best parodies are humorous takes that treat the source material with repect.

Shaun of the Dead

Galaxy Quest

Army of Darkness (person out of time becomes a leader against evil)

Airplane! lapped Zero Hour! so hard most people don't know about the existence of the latter

Spinal Tap. The reactions to it are telling enough: allegedly Steven Tyler didn’t think it was funny, and the Edge just wept.

Bugs Bunny far surpassed It Happened One Night. His manner of speaking, saying “doc,” and his obsession with carrots are a direct parody of Clark Gable’s character from that movie, but modern audiences don’t realize he’s a parody at all and instead assume the carrot thing it based on rabbits’ real dietary preferences.

Amish paradise. I find the song better than the original(s)

Cunk - parodying Attenborough and cosmos style docs

Starship troopers - more of an active ignorance of source material

Happy Gilmore

Blur - Song 2 was intended as a parody of American rock and is laden with nonsense lyrics. It's their most known song in America by a wide margin and might even be their most known song globally.

Woohoo

The Onion is way better than real life, especially currently.

The Orville

Walk Hard: The Dewey Cox Story

You'll never look at a music docu-drama the same.

As an animation nerd I gotta mention Shrek. As a parody of "Disney princess movies" it killed the entire genre dead.

The only time Disney tried to play the tropes somewhat straight again was the Princess and the Frog, and THAT was a major flop (though racism probably also played a part in that).

Since then Disney only made remakes or titles like Frozen that spend 70% of their runtime mugging at themselves and poking fun at their own tropes (... While still circling back to them anyway and failing to make any point or commentary)

On a less "this made a major cultural impact" note and more of a "this personally completely altered my entire sense of humour and replaced the original in my heart" -- SnapCube's Realtime Fandub Games Sonic Adventure 2

Oh oh ohohoh! Just remembered JoJo's Bizarre Adventure. Very much a manga that was poking fun at contemporaries like Fist of the North Star... And while it didn't outlive or outdo them per se, it definitely gained a life of its own, continuing to this day and actually being quite influential in its own right.

Idiocracy started as a parody, and is now becoming a reality.

Yugi Oh The Abridged Series

Teenage Mutant Ninja Turtles were originally a parody of Daredevil. I think they have surpassed it in popularity.

Spaceballs.

Does idiocracy count?

Idiocracy.

Sometimes the Simpsons parodied things so well, that it's only later on in life that I realize iconic and hilarious Simpson moments were actually parodies.

The Cape Fear episode. The Citizen Kane episode. The Thelma and Louise episode. The Planet of the Apes musical.

fuckin' classics

Kung pow: enter the fist

Dragon Ball Abridged

It's been a while, but as far as I can remember, I liked Hot Shots way better than Top Gun.

Rosencrantz and Guildenstern Are Dead is better than Hamlet. Sure, it had the benefit of an extra couple of centuries of progress in art, but I think it still counts.

Deadpool It was a parody of DCs Deathstroke, right down to the guy's name Slade/Wade.

Discworld

I have not seen the original, but Airplane! for sure.

Don Quixote
The Princess Bride
Cold Comfort Farm

Steamboat Willie was a parody of Steamboat Bill Jr., a Buster Keaton film.