One of the biggest factors in the success of the MCU has been the source material. Without the decades of expert storytelling that Marvel's comics have laid down, the MCU wouldn't exist; very few of the stories are actually original or if they are, they still borrow lots of elements from the comics and it looks like it'll that way for a long time.
The MCU has proven it can tell stories without taking everything from the comics but with so many tried and true ideas, they would be fools not to use the years of source material. Conversely, there are some stories the MCU should stay away from for all kinds of reasons.
10 Would Work For The Movies: The Inhumans (1998) — it's everything good about the Inhumans & if done right could wash the bad taste out of everyone's mouth
The Inhumans were poised to be a big part of the MCU, taking the place of the X-Men in Marvel's big-screen universe. They were given a try out in the comics, one that was remarkably unsuccessful and soured fans on them immensely. They were relegated to TV, where they failed miserably and all plans for a film with them have been scrapped.
However, if Marvel Studios ever decides they want to do an Inhumans movie, they should look no further than 1998's twelve-issue maxi-series, The Inhumans. A twisty thriller full of great character work and royal intrigue, it's everything good about the Inhumans and if done right could wash the bad taste out of everyone's mouth.
9 Wouldn't Work For The Movies: the number of changes that Earth X would need would make it into a different story
Earth X is an unsung masterpiece, a possible future for the Marvel Universe that sees everyone get superpowers at a terrible cost, while also revealing the secret behind everything. It contained a history lesson about the Marvel Universe, laying bare the origins of the most important heroes on Earth and tying it all together masterfully.
The problem in adapting the story comes in just how different the cosmology of the MCU is compared to the Marvel Universe and the lack of a lot of important characters that make up the backbone of the story. It's possible it could be done at some point in the future but the number of changes that would have to be made to it would make it into a different story.
8 Would Work For The Movies: The Sentry is the kind of thing the formulaic MCU needs
The Sentry was a story about a Marvel-ized Superman pastiche that did what Marvel does best: give human foibles to the superhuman. The story of Robert Reynolds and how he overcomes his mental issues and self-imposed boundaries to again become one of the most powerful heroes on Earth is a great one and is the kind of thing the formulaic MCU needs.
The Sentry is a psychological story as much as it's a superhero one, which sets it apart from the run-of-the-mill MCU story. The Sentry himself is also a fascinating character, one who has a million uses and could bring a lot to the MCU.
7 Wouldn't Work For The Movies: what Squadron Supreme does with superheroes isn't particularly groundbreaking anymore
Squadron Supreme doesn't get enough credit for just how groundbreaking it was, being overshadowed by Watchmen, which started shortly after the twelve-issue series began. Squadron Supreme used a Justice League analog team to tell a story about how power can corrupt those with even the best intentions and other heady themes not touched on in comics of the time.
The problem with adapting it is two-fold; what it does with superheroes isn't particularly groundbreaking anymore and the fact that characters borrow heavily from the Justice League would confuse viewers, making it seem derivative. It's a shame because an MCU Squadron Supreme adaptation would be amazing.
6 Would Work For The Movies: Wolverine: Not Dead Yet is one Of Wolverine's most underrated stories & would make a killer movie
Everyone knows that it's only a matter of time before Wolverine gets his own MCU movie and a great choice for a story to base it off of would be Wolverine: Not Dead Yet. It pits Wolverine against the White Ghost, a spy and assassin he worked with in the past, one who has spent years trying to figure out a way to kill the Canadian mutant.
While the story took place during Wolverine's bone claw period, it would still work if he had his adamantium and show viewers a side of Wolverine they haven't seen yet; more of a spy and killer than a superhero, giving them a glimpse into his sordid past. This is one Of Wolverine's most underrated stories and would make a killer movie.
5 Wouldn't Work For The Movies: New X-Men: E Is For Extinction is just too much for a casual audience
New X-Men and its opening story arc, E Is For Extinction, was a huge change of pace for the X-Men, the beginning of a revolution that would change the way fans and future creators looked at the team. The story threw a lot at readers and is definitely a bit much for less devoted audiences.
E Is For Extinction is an extremely advanced X-Men story, combining new, big concepts with tried and true superhero action and, honestly, movie fans aren't ready for the type of story it is. It's just too much for a casual audience and with its rather horrific act of mutant genocide, it's quite certain that Marvel Studios will be skipping this one.
4 Would Work For The Movies: Avengers: Under Siege has long been considered one of the best Avengers stories of all time
It pitted the Avengers against the Masters of Evil, a team of some of their deadliest foes led by Baron Zemo, who had out-thought the Avengers at every turn. It's full of epic moments and the kind of huge superpowered battles that the MCU does so well.
While the story would definitely need some tweaks, it would take a lot less than most would imagine and the story itself fits into the MCU wheelhouse perfectly. The MCU Avengers have rarely faced a group of foes like the Masters of Evil and it would make for great big-screen spectacle.
3 Wouldn't Work For The Movies: Secret Empire would have to be pruned down immensely to work on the big screen
There are lots of reasons Secret Empire would not work as a movie. For one, at this point, Chris Evans isn't under contract and the story wouldn't work as well with another character in his place. Second, MCU audiences love Captain America way too much to even think of him as a bad guy. Finally, the MCU's Hydra is much more closely related to the Nazis than the comic Hydra, making one of the many criticisms of the comic ring even truer.
Besides all that, Secret Empire is a story that is basically all squandered potential and would have to be pruned down immensely to work on the big screen — a pruning that the comic itself desperately needed.
2 Would Work For The Movies: Fantastic Four #48-50 is a story that needs to be told in an FF movie
Fantastic Four #48-50 pit the team against the menace of Galactus and while it definitely shouldn't be the way the team is introduced to the MCU, it's a story that needs to be told in an FF movie. It shows just how resourceful the team is and how they win their battles — using brains as much as brawn.
This classic story would be rather easy to adapt, with the introduction of Galactus and his herald, the Silver Surfer, opening up a whole new can of worms for the MCU. As much as people want Galactus to be the next big bad, this story needs to be done exactly as it was in the comic to put some shine on the FF.
1 Wouldn't Work For The Movies: Civil War II relied heavily on the Inhumans, something that wouldn't work in the MCU
Civil War II was a lackluster event meant to cash in on Captain America: Civil War but it failed in every conceivable way. People didn't like the story, which was basically Minority Report with superheroes and it didn't do any favors for any of the featured characters — it took Iron Man off the table and made Captain Marvel look terrible.
It also relied heavily on the Inhumans, something that wouldn't work in the MCU. The lack of Tony Stark and the fact that framing Captain Marvel as the bad guy would hurt her already precarious position means this one should never see the big screen.