A great performance can bolster any movie, be it a micro-budget indie or a $200 million tentpole, and similarly, so too can a terrible performance detract from an otherwise excellent one.
These big-budget movies were largely acclaimed by both critics and audiences for their directorial skill and array of strong performances, which helped fan away the stereotype that blockbuster movies are soulless cash-grabs beyond all else.
That said, there's that one performance that just sticks in the craw of even the most hardcore fan, that one actor who lets the side down with their tone-deaf, dull or straight-up effortlessly bad acting display.
These performances all provide a significant distraction from the greatness happening around them, in part exacerbated by poor writing and/or a lapse in directorial integrity, making you wish literally anyone else was cast in the part.
Here are the 13 worst performances in otherwise awesome blockbusters...
13. January Jones (Emma Frost) - X-Men: First Class
The Movie: Arriving amid a fairly tepid wave of audience expectations, Matthew Vaughn's X-Men prequel erased a lot of the fanboy ire built up by X-Men: The Last Stand with its strong reinvention of numerous iconic superheroes, clever and compelling plot, and thrilling action sequences.
The Performance: While some might try and argue that Emma Frost is meant to be a bit cold and robotic (it's in the name after all), that does little to excuse Jones' charmless, oddly un-sexy performance, failing to cement her as either an appealing siren or a particularly threatening mutant.
It was enough to convince most that Jones' acclaimed work on Mad Men exhibited her full range of acting abilities, and she basically rehashed that to highly diminishing returns here. She sucks so much that they killed her off-screen in Days of Future Past.