The Marvel Cinematic Universe has already adapted several popular and beloved Marvel Comics storylines such as Civil War, Planet Hulk, Infinity Gauntlet, and Winter Soldier across its films with more, such as Secret Invasion, on the way. Marvel has a long history and a lot of interesting plotlines to mine for movie magic, so there could still be plenty more on the way.
However, not all Marvel Comics stories are created equal, and there are some that are so weird that they would be a challenge to recreate--and that's an enticing concept in itself. WandaVision already proved Marvel can adapt some unconventional superhero drama in compelling fashion, so why not dive back into the well?
10 And They Shall Call Him Champion
This is a brilliantly weird and beloved piece of Marvel history. It took place in Marvel Two-in-One Annual #7, which was a series that mainly focused on the Thing of the Fantastic Four teaming up with other Marvel heroes. However, in this story, he teams up with some of Marvel's strongest heroes like Thor, the Thing, and the Hulk to fight an Elder of the Universe known as the Champion.
The Champion claims to be the best fighter in existence and wants to challenge the strongest of Earth's heroes. He beats them all with ease, except the Thing. The Thing keeps getting beaten down but gets up for more. As expected, this bit of grit and will impresses the Champion, and he grants victory to the Thing.
9 The Serpent Crown
This is one of several times that the Avengers fought the Justice League--but not THE Justice League. This story has a few somewhat disparate parts to it that still make up a whole plot. Classic Avengers and FF foe Kang the Conqueror is trying to get an artifact of unimaginable power known as the Serpent Crown and, in doing so, scatters the Avengers across time and space.
In doing so, Kang sets up the Avengers to fight Marvel's not-Justice League, the Squadron Supreme, starring members like Hyperion, Nighthawk, Power Princess/Warrior Woman, the Whizzer/Speed Demon/Blur, and Doctor Spectrum.
This also led to that time that a cowboy was on the Avengers for a while-- a fella by the name of the Two-Gun Kid.
8 The Illuminati
This is more of a spread of stories that could be pulled together for an overarching plot. The Illuminati is a team of Marvel leaders and big brains: Iron Man, Mr. Fantastic, Professor X, Black Panther, Yellowjacket, Black Bolt, Namor, and Doctor Strange. They unilaterally made several decisions to shape the history of the Marvel Universe at several points. They also kept getting outed, with the likes of Captain America, the Hulk, and other Avengers being enraged by their actions.
In other words, this could be a case study on the hubris of man and how badly a small group like this thinking they know better can actually cause more harm than good.
7 Damnation
Speaking of the hubris of man, Doctor Strange pulled another pretty big uh-oh with the whole city of Las Vegas at one point. After the entire city was wiped out by Hydra during Secret Empire (let's not talk about that one), Doctor Strange tried to resurrect the entire city with powerful and untamed magics.
This led to Hell rising with Las Vegas, and Mephisto spreading havoc across the Earth. Doc Strange had to enlist the help of the Midnight Sons--Ghost Rider, Moon Knight, Wong, Scarlet Spider, Blade, Doctor Voodoo, Elsa Bloodstone, Iron Fist, and the Man-Thing--to undo his huge mess-up. It also led Ghost Rider to become the King of Hell for a while.
6 Shadowland
This is another example of heroes coming up with ultimately disastrous plans. Daredevil, for a time, thought he could control the organization of villainous ninjas known as the Hand by becoming their leader. This didn't work out, and he was possessed by the demonic Beast that the Hand worships. He ended up erecting a vast prison in Hell's Kitchen and throwing anyone and everyone in it.
The Avengers tasked a group of street-level heroes--Luke Cage, Iron Fist, Moon Knight, Ghost Rider, Wolverine, Spider-Man, Elektra, Misty Knight, Colleen Wing, Shang-Chi, and the Punisher--with putting a stop to Daredevil.
5 House/Powers Of X
This is a very recent story and actually wouldn't be a bad way of introducing the X-Men into the MCU. A mutant named Moira MacTaggert has this very specific ability to remember her entire life and be reborn back at the time and place of her birth after death. She uses this to unite all the warring mutant factions on a living mutant island named Krakoa and become their own nation-state.
This creates a utopian mutant society led by the likes of Professor X, Magneto, and Apocalypse. They're also able to resurrect upon death thanks to the powers of a group of mutants called The Five. The rest of the world is startled by this development, and there is a lot of foreshadowing of an apocalyptic war between mutants and man-made AI.
4 The Death Of Captain Marvel
This could be something of a prequel to Captain Marvel. Before there was Carol Danvers, Monica Rambeau, Genis-Vell, or Noh-Varr, there was Mar-Vell. He, or she in the movie, was Captain Marvel in Marvel Comics and had a long-standing rivalry with Thanos.
This might require a bit of retconning in the movies, but Mar-Vell died of cancer because of a villain known as Nitro, the Exploding Man. The Kree offered a cure if Mar-Vell renounced Earth and returned home, but he refused and died a slow and painful death with all of Marvel's heroes surrounding him and mourning. This would be difficult to recreate in the movies as they are, but it would be a cool thing to see on the big screen.
3 Annihilation
This was a space epic that involved the Fantastic Four villain Annihilus escaping his home realm of the Negative Zone and swarming the Marvel Universe with his ravenous insectoid army. This led to the modern-day formation of the Guardians of the Galaxy and found them along with Silver Surfer, Quasar, Nova, Ronan the Accuser, the Super-Skrull, Galactus, and most of the species in the Marvel Universe fighting back against the hordes.
It's a beloved cosmic epic that forever changed the way the cosmic side of Marvel Comics looks and feels.
2 The Korvac Saga
This started with a villain called Michael Korvac, who fought the original Guardians of the Galaxy (from the year 3000, yes it's confusing) coming back to the present day, gaining unimaginable power from Galactus' ship. Korvac becomes a god and comes to Earth.
This leads to the Avengers, the Guardians of the Galaxy, and a few other heroes fighting against Korvac in the present day, all dying, and then being resurrected by Korvac in his grief before he kills himself. It's a bonkers story.
1 The Thanos Imperative
Finally, there is the Thanos Imperative. What if Mar-Vell performed a profane ritual to kill Death so that he could live forever? This answers that question, with a race of Lovecraftian gods called The Many-Angled Ones mutating all life in a parallel universe to become immortal, powerful, and grotesque. Ultimately, they invade the regular Marvel Universe and try to take over because they've run out of space in their own universe.
This alternate universe was called the Cancerverse, and it was ultimately stopped by Nova and Star-Lord taking Thanos to the Cancerverse and killing the Cancerverse Mar-Vell in his own reality, causing it to collapse on itself and killing everything inside--Thanos, Star-Lord, and Nova included.