The Killer Shrews

Indiana Jones and the Dial of Destiny! has some really goofy CGI. Sometimes it looks like slapstick

In the Name of the King: A Dungeon Siege Tale. Or really anything by Uwe Boll, but that might be his magnum opus. Honorable mention to Bloodrayne (but not the sequel).

If you want to see Oscar award winners embarrassing themselves in the worst movie of their career, Uwe Boll is your man.

My friends and I watched Morbius high as a kite and it was hilarious...we couldn't finish it tho

Not sure about "ever seen", but I recently watched The Room, and The Disaster Artist.

Revenge of the Sith. I have very fond memories watching the infamous "NOOO!" scene over and over with my friends, laughing harder than we ever had in our lives.

Lord of the rings, the first one. It was a hilariously waste of time and I wish I had those hours of my life back.