Godzilla 1998 And Godzilla 2014
The 1998 Godzilla is pretty infamous for taking Godzilla, a creature that blurs the line between radioactive science and mythology, and ripping every ounce of mysticism from it. The biggest plot point of the movie is the revelation that Godzilla is asexual, and because this is a film that was made in 1998, a lead character responds with "Where's the fun in that?" The cast of characters, with personality traits like "has a funny name," "carries camera," and "French," scream most of their lines, and remain engaging simply because, in a movie about a giant atomic monster rampaging through New York City, they're still the loudest things on screen.
On the other hand, the 2014 Godzilla can't decide whether it wants to provide a science-y look at Godzilla or a folkloric one, and so it drops the former completely about two-thirds of the way through. This is hard on the lead characters -- a soldier, his scientist dad, and another science dude -- as they are not really good for anything other than reading Godzilla-related encyclopedia entries out loud in order to progress the plot.
So why not switch them? The cast of the 1998 Godzilla is in no way prepared to handle a storyline that requires them to take lectures in Kaiju biology seriously. They're self-aware in that bizarre late '90s way, where every serious situation needs someone, preferably Martin Lawrence, shouting a punchline to prove that they, like you, aren't actually invested in what's going on. They're way too cool for that. So just stick that cast in the 2014 Godzilla, where they can scream and shout and run around while awesome monsters wrestle in the background.
And if you put the straight-faced cast of the 2014 film in the 1998 film, you'd be able to take the movie seriously, or at least appreciate the movie for taking itself seriously. That cast is perfect for longwinded conversations about Godzilla's sex life. It includes Bryan Cranston, who is watchable in anything -- doubly so if that anything happens to include a very passionate proclamation about monster boners.
X-Men: The Last Stand And X-Men: Apocalypse
X-Men: The Last Stand never quite gets as big as it wants you to think it is. Jean Grey has turned bad, Magneto is moving the Golden Gate bridge, and you have the Juggernaut! But on the flip side, Magneto's team has gone from rogues like Mystique and Toad to Multiple Man and a dude with quills. Wait, let me check Google to see what his name was. I bet it's "Quill." Yep, it's Quill. Never change, X-Men.