What shows/movies are absurdly stupid but fun to watch with friends?

I love Iron Sky for this. Nazis on the moon. It's satire all the way through. Such a goofy film but a lot of fun.

The Evil Dead trilogy.
A younger friend of mine had started playing the Evil Dead game with some of his friends but had never seen the movies. I'd not watched them in years, so I invited him over to marathon them one weekend. We drank, ate pizza and did the whole trilogy, and we had an absolute blast. He loved how different each movie was, especially Heart of Darkness. How each one gets sillier than the last.
A few months later, Evil Dead Rise came out in the cinema, so we had to go see it. While this was much more a straight up horror movie (with a small amount of the Evil Dead silliness), I still enjoyed it (I find horror movies quite funny, like an emotional rollercoaster), but he was hiding behind his coat the whole time, terrified of what was happening on screen. That made it even funnier for me.

Hot Fuzz is plain stupid but so fun. So is Taxi Taxi, if you've never seen it.
- hot fuzz is not plain stupid, it's advanced stupid. it's a dumb movie made by really intelligent people.
- Hot Fuzz is incredible. There isn't one wasted line in that script

Tucker and Dale vs evil is a over the top gory comedy slasher and I loved it when I watched it as a teen. It may not have aged well though
Other fan favorites are zoolander and tropic thunder

Moonfall (2023), seen it several times with friends, highly recommended
- Fuck me that movie was so stupid. I can’t believe I finished it (watching alone).

You gotta check out the Neil Breen movies. Here's a trailer for one of his movies, Twisted Pair.
They're absolutely awful to watch alone and great to watch as a group. I still can't decide if he's self aware or not.

Trailer Park Boys - para documentary comedy series showing life of people living in a trailer park

My top series for this is "Hi-sCool SeHa Girls", a 3D anime about three Sega game consoles who have been anthropomorphised into highschool girls. they go on adventures inside of lesser-known sega branded games, and the episodes are a mix of legitimately funny visual gags, good storytelling, bad storytelling, and both decent-quality cgi and extremely low-quality video editing. It's the most fever-dream-like show I've seen.
- Yeah thats going on the list
  
  It's free on tubi!

Nudist Colony of the Dead is awful and fantastic at the same time. I love getting a friend to go into the movie blind.

The day I got my best bud fucking blazed out of his mind to watch it has to be one of my favorite experiences.

My kids enjoyed "Evil Bong" and "Evil Bong 2" they are awful but still kind of funny and quite amusing in their way.

Garth Marenghi's dark place, rifftrax/mst3k, Young Frankenstein, duck soup, Joe Bob's has a bunch of shlocky horror movies mixed in with classics they do intros and interrupts like the old public access/cable monster movies

Kiss, Kiss, Bang, Bang
Hilariously dry comedy with the late Val Kilmore as a sassy gay man. Every other movie I wanted to suggest was already posted here. These are all great choices!

Letterkenny, lot of quotable dialog between the characters, unexpectedly witty considering the backdrop of a small Canadian hick town.

Olympus Has Fallen
London Has Fallen
The plot is so ridiculous, its actually comedic.
- If you haven't seen Angel has fallen - rectify this immediately. I'm fairly certain that Nolte just wandered on set wearing his own clothes and they were like, "Great! Let's shoot!"

Definitely wacky cartoons like Adventures of Sonic The Hedgehog or maybe season 1 of Reboot (part way through season 2, so I don't know whether the rest of the seasons are as light hearted as season 1), both shows you can laugh at the obsurdities of it all and in Reboots case laugh at the very outdated animation.

Anything where the plot literally does not matter so you don't necessarily need to pay attention to it to have fun. Like a lot of comedies or action movies.