6. Moira MacTaggert - X-Men First Class (2011)
Before I get started on this one can I just say I LOVE Rose Byrne and I think she is a great actress, anyone doubting this check her out as Helen in 'Bridesmaids'. The reason she is included in this list is due to the character of Moira MacTaggert. Fielding as a love interest to Charles Xavier in First Class she is a C.I.A. agent who attempts to infiltrate Sebastian Shaw's Hellfire Club. In 'First Class' it is ultimately MacTaggert and Erik Lensherr that cause Charles Xavier's disability. The newly created persona of Magneto deflects a bullet fired by MacTaggert into the spine of Xavier. A minor role as Moira MacTaggert is played by Olivia Williams in 'The Last Stand', talking about the genetics of mutants, seen next to Beast at Xavier's funeral and featuring in the hospital in the final scene. 'First Class' once again ignores the comic character of MacTaggert, depicting MacTaggert as American and not Scottish; secondly there is no mention of her and genetics at all.
The whole point of MacTaggert and Xavier's bond was the intelligence they shared and intentions to protect the mutant race. The main reason I don't want to see her back is because there is no purpose. At the end of the film Xavier erases her memory, this is the way it should stay. According to the comic books she doesn't last very long anyway, biting the dust after an attack by Mystique and Sabretooth.