The Mule
Yes, even movies as recent as 2018 can be lovable flops. 'The Mule' starring Clint Eastwood follows an old man who brings drugs across borders, but he's almost too good at his job. The DEA gets involved, and chaos obviously ensues. Comedians John Mulaney and Pete Davidson have both listed this as one of their favorites!
The Chase
The Chase was released in 1994 with a cast including Charlie Sheen, Kristy Swanson, Anthony Kiedis, and Flea from the band Red Hot Chili Peppers. In terms of total unbelievability, Sheen and Swanson's characters have sex during one of the car chase scenes. That's right--during! Also, Sheen plays a party clown. Insane from start to finish.