Modern superheroes are taking more money from civilians than their villains ever dreamed of, but it's the same few heroes being replicated more often than the dollar bills they're earning. Every Superman movie since 1980 has been a mistake, there are enough Batmen for a Bat-Basketball team, they rebooted Spider-Man like it was two hours of blue screen of death (which would still have been better than Spider-Man 3), and Iron Man has appeared in more entertainment gossip pieces than the actor who plays him.
Not so much method acting as giving the coolest guy the coolest stuff.
The whole point of superheroes is imagining things above and beyond what's possible. (I've already come up with 6 Ways to Build a Better Batman.) "Strong guy hits people" and "rich guy wins over the homeless" are already far too common in the real world, never mind cinema. The industry has gotten so desperate that news of an Ant-Man movie wasn't followed by laughter and the real announcement. Ant-Man's only qualification for superheroing is being invented around the same time as tie-dye clothing and unprotected group sex, and being a worse idea than both. Comics are stuffed with superheroes who would make much better heroes.
The X-Men are the most diversely powered superhuman group in fictional history, so it's strange that their only spinoff is "White Guy With Knives, Twice." He's already come back from one unsuccessful movie that should have killed him off (Marvel may have confused superheroes with slasher movies). An angry man waving knives around isn't a movie franchise, it's your father carving Thanksgiving dinner.
"It's time you got an honest job doing situps all day like me!"
If you want spinoff movies -- and Marvel knows that every addition to the film franchise is at least $100 million, so they really do -- the X-Men have more interesting characters than every soap opera in history fighting to the death inside a nuclear reactor. And the most moviegenic is Hisako "Armor" Ichiki. Armor is a badass girl with a robot suit made entirely of psychic special effects. There is no nerd money that combination of niches wouldn't earn.
When she dresses in pink, it's to punch your face in.
Did we mention it can scale in size, making Armor the only person who can think "Pacific Rim is awesome" so hard that it actually happens?
Hisako doesn't take no drift from nobody.
An awesome female lead and an ability that kicks ass when it's active, but doesn't render her permanently immune from harm (it's hard to build tension when the hero's only power is "can't actually be killed," Logan). As a teenage girl who could stomp the sharpened weasel into two-dimensionality, she seems specifically written to take the piss out of Wolverine. And he's had two tries already.
When she flicks a V, it stands for "Very Badly Wounded."
Iron Man is more cinematically popular than popcorn. He's made more money for Marvel in our world than he ever did in his, and his entire power set is "making awesome new things." He's the perfect launch point for a spinoff. And the comics have already introduced one.
The Rescue armor
Rescue is what happens when Tony finally builds something that can't be misused by bad guys. The way he said he would three movies ago. I'm no security expert, but when your suits have been used in attempts to assassinate the president of the United States, you might not have reduced your contribution to terrorism.
"The real terror is what this techno-corset built for a man half my belt size is doing to my kidneys."
Rescue is an unarmed repulsor-powered protection and rescue system, and he gave it to longtime ally Pepper Potts because he knew he couldn't wear it for 40 seconds without hot-wiring a plasma cannon into the codpiece. And never mind civilians: Rescue could save superhero movies. Keeping these inhuman ass-kickers interesting has become a serious problem. We need new story structures beyond "Here's a good guy and a bad guy and some rocket punching and now just a good guy." Do you have any idea how bad things have to get before I say something bad about rocket punching? Rescue offers a whole new arena for awesome special effects: the superhero disaster movie.
Disaster movies are big business, but they've always been crippled by a ridiculous lack of real conflict. When your only hero against the rising oceans of bullshit is an earnest stubbly man with a laptop, you're just marking time till the 80-minute mark so he can shout "Wait a minute!" and technobabble it all away.
Now imagine a movie where someone could punch 2012 in the face!
And if any movie ever deserved it, it's 2012.
Instead of churning out villains who fail to threaten the immortally armored hero -- remember, it only took them two movies to shrug and say "Let's try that guy with whips" -- you can have your hero fighting an unlimited special effects-fest. A Rescue movie would be the ultimate crossover, not between heroes, but entire genres, a clash of cataclysm-level computer graphics in a whole new field of cinema excessexiness. And that field would be erupting into a supervolcano underneath a crashing space station.