Kitty's speech defending Nightcrawler from Stryker is incredible. It carries so much more weight given how much she feared and shunned him when first joining the X-Men. It's made even better when you consider the fact that Kitty is religious herself.
Stryker: You are call that thing human?
Kitty: More human than you! Nightcrawler's generous, and kind, and decent! He had every reason to be bitter, every excuse to become as much a demon inside and out, but he decided he's rather laugh instead! I hope I can be half the person he is and if I have to choose between caring for my friend and believing in your god, then I choose m-my friend!
Stryker replies to that by trying to gun her down, only to be shot himself by a random, unnamed cop. Because Stryker tried to shoot an unarmed little girl on his watch.
Mixed with tearjerker, Magneto arriving at the schoolyard after the murder of Mark and Jill, the two mutant children. Too late to save them, he takes their bodies out of the swing and lowers them to the ground, sparing them from a final indignity of being found by the schoolchildren in the morning and used as a method of intimidation against other mutants. Clearly distraught, and no doubt reminded of the horrors he himself experienced during the Holocaust, Magneto vows that no more innocent mutants shall die and that he will make their murderers pay.
Magneto: An execution. Not the first. Far from the last - only this time, the victims are children. So young... so innocent... to know such terror and pain. Their only crime - that they had been born. And for all my vaunted power, I was unable to save them. No more shall die - but for those responsible for this atrocity! Whatever the cost, however long it takes, I will hunt them down - and make them pay!