Every Transformers Movie Ranked From Worst To Best
5. Transformers: The Last Knight

Many consider The Last Knight to be the worst of the Transformers movies, but Michael Bay's final time in the director's chair benefits considerably from its go-for-broke weirdness.
This is a movie where Stanley Tucci is re-cast as a drunken Merlin who hangs out with the Autobots, Anthony Hopkins co-stars as a hammy, exposition-spouting old coot with a robot ninja for a butler, it's revealed that Hitler was assassinated by a Transformer, and Mark Wahlberg gets to swing Excalibur around.
A big part of the reason The Last Knight is fairly tolerable is the massively dialled-back sexism and racism - in large part due to casting the underage Isabela Moner as the female lead - not to mention a general lack of the embarrassing "humour" from previous movies.
Action-wise you know what you're getting here and it's all pretty tired by this point, to say nothing of the distracting ratio-switching during action scenes because Bay decided to shoot the film in about a dozen different ratios.
But it's about 10 minutes shorter than Age of Extinction, which is nice.