Us comic book fans are a passionate bunch, with connections to characters from the Marvel and DC Universes that non-fans are unlikely to ever understand.
When you grow up invested in the stories of heroes and villains like Batman, Captain America, and The Joker, it's impossible not to have strong feelings about how they should be portrayed on screen. Studio execs often have their own, very different ideas, of course, and that's led to some "controversies" about casting decisions which have sent shockwaves across the internet.
However, while fans have sometimes been justified in their outcry - Topher Grace as Venom? Really? - there are some occasions when we've ultimately been proven wrong.
There will always be those who maintain that studios made a bad decision, but the actors listed here all exceeded expectations and proved they were the best possible choices to play these heroes and villains...
10. Michael Clarke Duncan as The Kingpin
The late, great Michael Clarke Duncan blew us all away as Wilson Fisk in Daredevil, but he was among the first actors to face backlash for being a different race to how the character was portrayed on the page.
Even studio execs were uncertain about taking the chance, but they couldn't find a white actor physically imposing enough to play The Kingpin, and gave Duncan a shot. Thank goodness they did, because he was by far the best part of an otherwise disappointing film.
The final battle with Fisk and Daredevil was awesome, and sold by Duncan's stellar performance.
He delivered a comic accurate, pitch perfect take on this iconic baddie, and proved that studios could and should embrace diversity for a medium that introduced most key characters in a time where that was hard to find.
9. Chris Evans as Captain America
Visit an online message board, or indeed this very website, back in 2009, and you'll find that Chris Evans was not a popular choice to play Captain America in the MCU.
He may have done a good job as the Human Torch in Fantastic Four, but Steve Rogers is an entirely different matter, so it's no wonder there was some scepticism. It's not like Evans even had a string of hits to his name at this point in his career, and there was nothing on his IMDb page which suggested he might be a good fit for Captain America: The First Avenger's lead.
Kevin Feige proved he knew best, though, and Evans knocked it out of the park.
By the time Captain America: The Winter Soldier rolled around, the actor had made the part his own. Evans has become iconic in the process, and there's no way one-time fan-favourite picks like Jon Hamm and Armie Hammer would have done any better.
8. Chris Pratt as Star-Lord
"The 'chubby' dude from Parks and Recreation as Star-Lord? No freakin' way."
Well, that was very much the attitude online when Chris Pratt was cast as Star-Lord in Guardians of the Galaxy, but anyone who doubted the actor was soon shown to be way off base.
Pratt got ripped to play an MCU superhero, something that was evident when he showed up in Zero Dark Thirty looking surprisingly chiselled. With the right attitude and look to play Peter Quill, Pratt made the role entirely his own, and won the support of legions of fans along the way.
James Gunn and Marvel Studios got this one right, though no one believed it until the film was released in 2014!
7. Gal Gadot as Wonder Woman
Zack Snyder is responsible for casting Gal Gadot as Wonder Woman, and just like he plucked Henry Cavill out of relative obscurity and made him a household name, the filmmaker arguably did the same for this Israeli actress.
Gadot had starred in the Fast & Furious films by this point, but it's not like that's a franchise known for highlighting the acting abilities of its cast.
It's easy enough to understand why so many fans were horrified at the prospect of the actress playing Diana Prince in Batman v Superman: Dawn of Justice. While the 2016 film only gave them a glimpse of Gadot's take on the iconic hero, it was 2017's Wonder Woman that made it clear Snyder made the right call.
Wonder Woman 1984 has divided opinions, but Gadot's work still can't be faulted.
6. Zendaya as MJ
It wasn't abundantly clear who Zendaya was playing heading into Spider-Man: Homecoming, but most fans figured "Michelle" had to be MJ.
As well as being a different race to the comic book version of this love interest, photos of Zendaya in the role didn't exactly bring to mind the supermodel from the source material. The actress proved to be a likeable presence in the reboot, but Marvel Studios might not have helped themselves with that "My friends call me MJ" reveal!
Spider-Man: Far From Home, however, established MJ as a perfect love interest for Peter, and Zendaya really got chance to show us what she could do.
The backlash here was nowhere near as bad as when Shailene Woodley was cast in the role for The Amazing Spider-Man 2, but Zendaya still proved a lot of people 100% wrong.
5. Idris Elba as Heimdall
When Idris Elba was cast as Heimdall in Thor, he was already one of the most talented actors working at the time.
That remains the case today, and we can only hope the same sort of racist backlash the Brit suffered back then wouldn't be as prominent now.
Some so-called fans were left frothing at the mouth over the prospect of a Black man playing a Norse God, pointing out that Heimdall had been described in mythology as the "whitest of the gods." It was a ludicrous, vile argument that highlighted some problematic parts of fandom that sadly remain to this very day.
Elba didn't get an overly meaty role as Heimdall in the MCU, but effortlessly did this minor comic book character justice.
4. Ben Affleck as Batman
Daredevil was a mess of a film, but Ben Affleck spent the years that followed establishing himself as a top tier actor and filmmaker.
Unfortunately, that still wasn't enough for some fans to get past his time as the Man Without Fear. The news Affleck would play Batman was met with widespread scorn online, and death threats, promises of boycotts, and heaps of vitriol were quick to follow. It was crazy.
Batman v Superman: Dawn of Justice eventually arrived, and while some of Zack Snyder's creative decisions upset fans, everyone was soon on board with "Batfleck."
As the DCEU's Caped Crusader, Affleck knocked it out of the park, playing a world-weary experienced Batman with ease. It says it all now how desperate fans are for his version of The Batman, and the excitement that surrounds the actor's return to the role in The Flash next year.
3. Michael Keaton as Batman
Ben Affleck isn't the only big screen Batman to receive a negative response after being cast.
The internet wasn't an issue in the late 1980s, but one angry fan penned a letter to the Los Angeles Times they must be kicking themselves about today.
"He might have made a good Joker, but his comic style, which he seems unable to shake (but can amplify), has doomed this promised 'serious' treatment of Bob Kane's character to the same tired, boring level of artificial "camp" that made the TV series a hit yet simultaneously doomed it to an early cancellation," it read back in 1988.
That gives you an idea of how fans felt about Keaton, best known for his comedic work at the time, playing the Dark Knight. Instead, he delivered a definitive take on the DC Comics superhero, and like Affleck, fans can't wait to see him return in The Flash.
2. Robert Downey Jr. as Iron Man
Before Iron Man, Robert Downey Jr. had definitely delivered some excellent performances, but he'd also become best known for his personal problems, and an infamous mugshot.
It's not that fans didn't think Downey could do a good job as Tony Stark, but he certainly wasn't a natural fit for the role, and it was easy enough to imagine the decision backfiring on Marvel Studios. Had anything gone wrong, who knows if the MCU would even exist today.
Downey would ultimately prove that those who had faith in him were correct, putting Iron Man on the map, becoming one of the highest-paid actors ever, and the face of the MCU.
He also proved that everyone deserves a chance to play these comic book characters.
1. Heath Ledger as The Joker
As we're sure you've now noticed, fans far too often judge an actor on their past performances, forgetting that their job is to reinvent themselves on screen from role to role.
Heath Ledger having starred in Brokeback Mountain surely meant he couldn't play The Joker, correct? That was the narrative online when he was cast, but little did anyone know how much the late actor would give to this role (many have argued that getting into the Clown Prince of Crime's mind might have even contributed to Ledger's decision to take his own life).
The Dark Knight remains one of the best superhero films ever made, and much of its success can be credited to Ledger.
He won a posthumous Oscar for his work in the film, and it's hard to imagine Ledger ever being bested as this character on screen. Joaquin Phoenix gave it a good try, but this actor really made The Joker his own.