What is the WORST movie you have EVER seen?
For me, it would be 'Ghostbusters'.
Hardcore Henry or Romper Stomper.
Worst Movie? Wheels of Fire
FOR YOUR CONSIDERATION:
The Lighthouse. The 2019 horror drama starring Willem Dafoe and Robert Pattinson as two lighthouse keepers who descend into madness after being stationed on an island for....four weeks. What?!?! You can't handle four weeks on a remote island...were there no other jobs available to you?? Dafoe and Pattinson do probably their best (worst?) over-acting of their careers in this. The director surely abandoned them. But it's hard to "descend into madness" and not look ridiculous. Even for these two actors who are normally great in other movies.
Also, The Lighthouse barely has a plot. These two men are basically on this island without anyone else...and it's TOUGH, dude! There is a sub-plot around mermaids, one of which Pattinson has sex with, but I assume this is a delusional encounter within his mind. The mermaid is stranded on land and is tangled up in weeds. Is this mer-rape??

Other than this slim storyline, it's just the demanding, gruff older superior harping on the newbie employee at every turn. Boring, repetitive movie cliché, there.
The Lighthouse is directed and co-written by Robert Eggers, who was behind the wonderful 2015 movie The Witch (starring Anya Taylor-Joy, who is now better known for The Queen's Gambit). But Eggers dropped the ball with this one. In order to create mood, he uses black and white cinematography and films the movie in a rarely used screen ration where the movie shows on the screen in a square shape, rather than rectangular. I suppose he meant to "box in" the viewer and make us feel claustrophobic. I'm sure that's what whoever saw this movie in the theatre felt like!
So this is my current selection for Worst. Movie. Ever.