"A fine movie and a great addition to the X-Men mythos"
Anyone who knows the comic book history of the X-Men knows that the action usually took second stage to the character interaction. Singer managed to pull together an excellent cast for this purpose. Ian McKellen did a wonderful job in bringing the menace that Magneto harbors but also played out the dichotomy of his position in the mutant universe. Magneto was always a sympathetic character who just happened to land on the wrong side of the fence according to his old friend Professor X who was played by Patrick Stewert and who seems to be born to play the role. Furthermore, Magneto's opening sequence and origin as well has his frequent references to being in a concentration camp add to the sympathy factor. This is very important to in the framework that Brian Singer laid down for X-Men. Other welcomed performances come in the form of Bruce Davison's Senator Kelly and Hugh Jackman's Wolverine. In the comic books Wolverine is short and stocky and very powerful and although Jackman was rather tall he defined the character very well. On the other hand Tyler Mane's performance as Sabertooth is laughable and he doesn't come close to representing the complexity and nature of that character.
The film deviates from the storyline in the X-Men books but I found these changes to be easily swallowed as Singer maintained the tone of the books while compacting decades of stories into one film. Having said that, I would really have liked to see Rogue in her typical flying and super strength fashion even if it never explained the Carol Danvers connection (although I believe some exposition could have dealt with this issue or it could have been covered in a sequel). From the opening sequence, to the revelation that the senate is considering passing the "Mutant Registration Act" there is a very moody undertone to the film that is compounded by Singer's direction and wonderful cinematography as well as Michael Kaman's score. This grim undertone is important in the X-Men mythos and is very present in the books. Singer deals with the X-Men in a minimalist fashion most probably due to budget constraints but he manages to keep the story fun and moody at the same time.
Brian Singer's X-Men is a film for the fans and in so there are plenty of Easter Eggs for the keen eye. The movie is an overall enjoyable experience with great direction and satisfying acting but is ultimately constrained by its budget.