1. Magneto
Naturally there can only be one X-Men villain at the top of the pile. Far from just a bloke who can control metal while wearing a silly-looking helmet, Magneto - along with Professor X - encapsulates all that X-Men is about; whereas Charles fights to stay good in the face of oppression and persecution, Magneto has decided to become the monster humanity thinks he is. Ian McKellen obviously brought as much gravitas to the role as he always does in the first trilogy, while Michael Fassbender gives the younger Lehnsherr a real drive and fury in the prequels. Rather than jarring, both performances effectively illustrate different sides of the same man. The fact that he has such a traumatic origin story and was once best friends with the leader of the X-Men makes Magneto all the more interesting. In fact, he's not just the best X-Men movie villain, but one of the strongest comic book movie villains ever. Who's your favourite X-Men villain? Give them a shout out in the comments.