Everyone loves a good plot twist. Whether that be in film, TV, novels, or comic books, a good story can be made great by giving the world something it just didn't expect.
Over the years Marvel has been responsible for some of the best twists in the business - or worst, depending on your viewpoint - but no matter which side of the argument you come down on, you can't deny that each one has made for some interesting reading, if nothing else.
Maybe it's the truth behind Wolverine's refusal to unsheath his claws, or maybe it's the answer to who really lurks behind Xorn's mask. Whatever story manages to get your pulse racing at the final reveal, there is no arguing that the writers and artists involved have done their job.
Not every entry on this list will be universally accepted as great - some might even have you screaming at your screen, but there is no denying that each one is here on merit.
Each one has left its mark on comic book lore, for better or worse, and span Marvel's entire library, from the Avengers, to the X-Men and beyond...
10. Skrull Spies In Secret Invasion
When a group of Super-Heroes, consisting of Iron Man, Professor X, Doctor Strange, Black Bolt, Mister Fantastic, and Namor, decided that the Skrull need dealing with permanently, they do it with a show of strength.
Attacking the Skrull Empire, with the idea being to threaten them with more violence if they show their little green faces on Earth ever again, things don't quite go according to plan as they're captured and studied, before fashioning a great escape.
When the Civil War storyline ends, it is revealed that Elektra is actually a Skrull plant and this, along with a few other things, is the jumping off point for the Secret Invasion.
It turns out that the Skrull have infiltrated nearly all points of Earth's Greatest Protectors, leaving spies in place of the likes of Henry Pym, Spider-Woman, and the Agents of S.H.I.E.L.D, to name just a few.
This puts the proverbial cat amongst the pigeons, meaning those who are left to fight not only have to battle the enemy but their own paranoia, not knowing who they can trust among themselves.