The Magneto breakout sequence in X-Men: Days of Future Past that featured Quicksilver was so incredibly fun. It was perfectly envisioned and brought to life, and I don't know one person who didn't love it. Producer Matthew Vaughn had another version of the scene that he would have done had he directed the film and not Bryan Singer. Vaughn was recently a guest on the Empire Podcast, and there he revealed his plan to break out Magneto:
“I had Juggernaut being thrown out of a plane at 20,000 feet, and using his head to go down a hole to get to the bottom of [The White House]. I had Beast saying, ‘I have a plan,’ and him replying, ‘What’s the plan? What’s the plan?’, and they go higher and higher and Beast was going to go, ‘This is it!’ and chuck him out the window. Then he goes smashing through [The White House] with his and Magneto goes, ‘Who the fuck are you?’”
Juggernaut was ultimately taken out of the story completely, and Evan Peters’ Quicksilver was basically used in his place, which was completely the right choice. Everyone ended up loving Quicksilver. I'm sure had we seen that alternate scene described above, we would have loved it, though, because we wouldn't have known about Singer's vision of Quicksilver. We just would have enjoyed what we got.
Vaughn went on to say that Singer's take was “the best scene in the movie.” Then he laughingly said, “I would have made the movie worse. The Quicksilver one was better.” What can you say? It really was.