In the mid to late 2000s, "fan casts" were commonplace online. Superhero films were few and far between, while the Marvel Cinematic Universe was still in its infancy (The Avengers was very much a pipedream). With so few characters on screen, it only made sense for excited fans to imagine which of their favorite actors could play these colorful heroes and villains.
As the years passed, and Photoshop became that little bit easier to use, fan casts have been replaced by "fan art."
Posters and images of varying quality depicting certain actors as comic book characters can be found online on an almost daily basis, and it's hard not to stop and ask whether they possibly even inspire what does end up on screen.
That's a question for another day, but there are some fan casting suggestions that are just so much better than those who got to play these characters in the films themselves. We start with those, then take a look at a few casting decisions we're still banking on happening in this new decade...
10. Bryan Cranston As Lex Luthor
When it became clear Lex Luthor would appear in Zack Snyder's Batman v Superman in 2016, fans immediately turned to one bald baddie to bring the supervillain back to the silver screen.
Fresh off playing Walter White in Breaking Bad, Bryan Cranston felt like the perfect choice to pit against Ben Affleck's Batman and Henry Cavill's Superman. Instead, Snyder took things in a different direction, introducing us to a much younger Lex playing by Jesse Eisenberg.
The actor's Social Network-style performance in the film didn't resonate with as many fans as the filmmaker hoped, and a lot of people have since theorized that Eisenberg's Lex was just the son of Cranston's Lex Sr.
It's a nice thought, but not an overly realistic one!
9. Charlize Theron As Captain Marvel
Former UFC fighter Ronda Rousey was a name that frequently came up while talking about Captain Marvel, but we're not entirely sure when she really can't act (please don't beat us up for saying that, Ronda).
However, up there with her as a top pick to bring the former Ms. Marvel to the MCU was Mad Max: Fury Road star Charlize Theron. Brie Larson has proven herself a great Carol Danvers, but looking at the comics, it's easy enough to understand why Charlize was a top pick for many.
She looks the part and could pull off Captain Marvel's commanding presence with ease.
There has to be another superhero film role out there for this Oscar-winner, but we're not sure some fans will ever get over not seeing her as Cap.
8. Jon Hamm As Batman
Similar to what happened with Jesse Eisenberg and Lex Luthor, Ben Affleck was no one's first choice to play Batman in 2016's Dawn of Justice.
The actor ended up surprising everyone, of course, and now has a legion of fans behind him.
That wasn't always the case, however, and when it seemed Affleck was battling Josh Brolin for the role, one fan suggestion that kept coming up - as it had done for years - was Mad Men star Jon Hamm. The majority was in agreement that he would make a great Bruce Wayne, but it never came to pass, and Hamm missing out on a role as big as this has seen his stock in Hollywood drop.
There's still time for him to play a comic book hero, but Batman has passed him by.
7. Katheryn Winnick As Black Canary
Vikings star Katheryn Winnick has been put forward for a lot of superhero roles over the years, and she was very nearly suggested as frequently for Captain Marvel as Charlize Theron.
On the DC side of things, however, it was Black Canary fans were anxious to see the actress suit up as.
You've only got to take one quick look at Winnick, and some of her past roles, to understand why. For whatever reason, it seems she just failed to make her way on to the radar of Warner Bros. That's a pity too, because a role like Black Canary would have cemented her as a true A-Lister.
Jurnee Smollett instead landed the role in this year's Birds of Prey film, and drew mostly positive reviews (even if the character barely used her powers).
6. Rosario Dawson As She-Hulk
We can't wait to see what Tatiana Maslany does with the Jennifer Walters role in She-Hulk, but had Marvel moved to bring this green-skinned lawyer to the screen a little sooner, the widely suggested Rosario Dawson would have been beyond perfect.
Instead, the actress found herself saddled with an underwhelming role in Marvel Television's Netflix shows.
As both sides of She-Hulk, it's hard to think of an actress better suited to this role than Dawson, and there are some sensational pieces of fan-art out there which will convince you of that.
We're not going to complain too much because Dawson has since landed the role of the live-action Ahsoka Tano in the Star Wars Universe, but it's hard not to mourn for this one!
5. Jensen Ackles As Captain America
When Marvel was on the hunt for Captain America, a lot of big names were suggested.
Some of those were cringeworthy (remember Mark Valley?), but fans got seriously heated while discussing who should play the live-action Steve Rogers.
One name that kept coming up, though, was Supernatural star Jensen Ackles. He hadn't been starring in the show for long, and was arguably still cutting his teeth as an actor. It's thought the insane amount of fan support may have got him a meeting at Marvel, but it just didn't pan out.
We can't imagine anyone better than Chris Evans now, but we hope there might be another big comic book role for Ackles after The Boys.
4. Bradley Cooper As The Flash
This will be a real blast from the past for many of you, but there was a time when a younger Bradley Cooper was the top pick among fans to play either Barry Allen or Wally West.
We're talking about the late 2000s/early 2010s, and one look at Cooper at that time should make it easier for you to understand why so many of us were intent on seeing him race into action alongside Ryan Reynolds's Green Lantern.
These two could have been a dream team on screen, in all honesty.
It never happened, though, and now Ezra Miller gets to call himself the Flash on the big screen. It's not all bad for Cooper, however, as he has a pretty sweet V/O gig as Rocket in the MCU.
3. Tom Hardy As Wolverine
Tom Hardy is currently rumored to be MGM's top pick for Daniel Craig's replacement as James Bond.
It's a nice thought, but the actor is perhaps a little old for 007, especially if longtime franchise producers Barbara Broccoli and Michael G. Wilson are looking for someone to be the face of the series for years to come.
The actor may be playing Venom in Sony's Marvel Universe, but he could easily fulfil the wish of many fans out there by making the leap into the MCU to suit as Wolverine.
Replacing Hugh Jackman was never going to be an easy task, but Hardy might just pull this one off.
2. John Krasinski As Mister Fantastic, Emily Blunt As Invisible Woman
We're cheating a little by putting this real-life married couple together, but just like Reed Richards and Susan Storm, they should come as a package if they're going to enter the MCU.
John Krasinski was once eyed to play Captain America, while scheduling issues forced Emily Blunt to drop out of playing Black Widow in Iron Man 2. Both have since expressed an interest in joining the Marvel Studios machine, with Krasinski clearly passionate about playing Mister Fantastic.
To cast anyone else at this stage would feel like a slap in the face to fans.
This is a bit of fan casting Kevin Feige has the chance to make real, and it would be such a missed opportunity to turn to anyone else to play these members of the Fantastic Four.
1. Jeffrey Dean Morgan As Flashpoint Batman
In an earlier iteration of The Flash, it seems Jeffrey Dean Morgan may well have been given the opportunity to play the Flashpoint Batman.
As the film has been passed from director to director, however, it's changed enough to that it seems Michael Keaton's Batman from 1989 will be taking on a similar role to the one played by Thomas Wayne's Dark Knight in the Flashpoint comics.
There's got to be a way to make this cameo happen as Barry Allen travels through the DC Multiverse.
Fans want it, Morgan wants it, and it would be a really tremendous way to pay homage to the storyline this film appears to be borrowing so much from.