Often, a good protagonist makes or breaks a film. After all, the protagonist is the viewer's main vehicle for alignment and therefore the backbone of the film, so having a compelling lead character is vital in order to get the audience fully invested in the film's story.
This doesn't always mean the protagonist has to be likable, since more morally complex and unsympathetic leads and antiheroes are often a great thing, as demonstrated by films like Goodfellas, The Searchers and The Wolf of Wall Street. That being said, such leads have to be done carefully in order to avoid alienating the audience.
In these movies, the protagonist was completely unlikable, which meant the audience had no-one to root for or identify with. Had these following 15 movies got the protagonist right, they might've otherwise been perfectly OK movies...
15. Mia - If I Stay
If I Stay is a terrible, eye-roll inducing teen weepie and it's made even worse by the protagonist, Mia Hall, being so unlikable.
Mia is whiny, ungrateful and so annoying she actually approaches Bella Swan territory at times. She just complains about everything and doesn't show any gratitude to anyone, including her family (who are actually really cool characters and definitely the best thing in the movie) or her blandly-written but undeniably devoted and adoring boyfriend Adam.
Speaking of that, the film is based around Mia having an out-of-body experience after a car crash that kills her family and leaves her comatose; she is debating over whether to wake up and live or die. While in this state, she mostly thinks about Adam, who she'd broken up with some time before and hardly gives her own family, who have just all died in an appalling tragedy, any thought. That's... pretty uncomfortable.
Mia is played by the talented Chloe Grace Moretz, who was more or less Hollywood's best young actor at that time. Alas, having learnt nothing from Carrie, a miscast Moretz mopes her way through another outcast role and gives her worst performance (bar Movie 43) to date.