pretty much all the "so bad, it's good" type movies like
The Room
Troll 2
Samurai Cop
Foodfight
Mac and Me
The animated Titanic movies (both of them)
Showgirls
North
Batman and Robin
The Happening
The Wicker Man (2006)
Silent Night Deadly Night series (1st one isn't actually all that bad, but the 2nd...woof)
The Sleepaway Camp series (again, 1st one isn't actually all that bad, but still...woof)
Santa Slay
Riki-Oh (surprisingly has good reviews, so it technically doesn't count for this list, but it's something that needs to be seen for the same reason as most of these movies)
Star Wars Holiday Special
and then just the usual basic movies that aren't "so bad, they're good" material, but not necessarily better-than-average movies, that I still enjoy.
Armageddon
Con Air
Demolition Man
Rocky IV
Hook
Space Jam
Good Burger
Varsity Blues
The Mummy series
Joe Dirt
The Waterboy (and pretty much any Adam Sandler comedy in the 90's, though I don't consider all of them "bad movies" per se)
Mars Attacks
Footloose (original)
and last, but certainly not least...Wet Hot American Summer
Those are all pretty much the first ones that come to mind. Could probably list a number of comedies and horror films, but nobody has time for that haha