King Arthur: Legend of the Sword (2017)

Ignoring the most unexplainable decision in modern cinema, giving
someone with Guy Ritchie's track record $200 million to make a
King Arthur film, this should be taught at film school. Not only
is it mind-blowingly terrible but across the board in editing,
shot framing, dialogue, screenplay, characterisation. It ended up
my worst film of the year.