8) Jean Grey (X-Men)
Famke Janssen was by no means a bad choice to play Jean Grey, and she certainly had her moments over the course of the three movies she appeared in (five if you include The Wolverine and X-Men: Days of Future Past). However, it was Bryan Singer’s decision to turn her into an object of desire for both Logan and Cyclops which not only negatively impacted those characters but also saw Jean portrayed far weaker than she ever should have been, and ultimately a shadow of her comic book self.
The love triangle between these three was admittedly toyed with for years in the comics, but Jean always stood by Scott Summers, a fan favourite character who came across as a whiny loser in these movies. Sure, Jean chose Cyclops over Wolverine by the end of X2, but did anyone actually care by that point? Nope, not at all. As a result, this is one romance best left forgotten, and with a younger version now being played by Sophie Turner, you have to hope that the franchise can move on from this little misstep and have Jean stand on her own as the powerful Phoenix.