X-Men 3 is okay, not brilliant, mostly because of what it does with Magneto. In previous films he and Xavier were opposite sides of the same coin - you could see where he was coming from, even if you didn't necessarily agree with him, and that made him interesting. But here he just goes for all-out bonkers and ends up no different from the "normals" that he despises so much.
Still, the movie has a higher body count than previous entries, the identity of some of those bodies comes as a surprise, and there are few sights more inspiring than a squad of six angry X-Men leaping into action to defend the innocent. I also have a friend in San Francisco who, given the city's propensity for earthquakes, refuses to take the tunnel under the bay; after seeing this he might also think twice about taking the bridge.
But, children, there are two lines that no character in a film should ever, ever speak, and Magneto utters one of them. It is: "what have I done?", as the full impact of the error of his ways finally blasts into his frontal lobe. Any script writer who perpetrates that authorial abomination should be hung upside down in a scorpion pit next to whoever thought it was a good idea in Episode 3 for Darth to go "No-o-o-o-o-!"
Which is the other one.