9. Harrison Ford & Josh Hartnett - Hollywood Homicide
Hollywood Homicide is a movie you probably haven't thought about in years - if ever - and honestly, it's largely only discussed these days due to the on-set turmoil between stars Harrison Ford and Josh Hartnett.
The 2003 buddy comedy followed the pretty typical formula of the grizzled vet butting heads with his younger, peppier partner, which was basically a case of art imitating life, given Ford's notoriously grouchy demeanour and Hartnett's more outgoing personality.
During shooting the pair were frequently at loggerheads, as Hartnett himself confirmed before the film was even released:
"There were times we would end up just sitting in the car when we were supposed to be doing a scene and neither of us would say anything for like an hour."
There are also apocryphal claims that Ford called Hartnett a "punk" and Hartnett dubbed Ford "an old fart."
Whether that's true or not, Hartnett added that they did manage to get along by the end of shooting, even if many noted their awkwardly stilted dynamic on the film's press tour.