Fans are shouting out who they want to be Christian Grey and Anastasia Steele in the upcoming erotic film "Fifty Shades of Grey."

While knowing who they want to play the individual parts, some already know which stars they want paired up to play the kinky couple.

Books & Review put together some couples who could play Ana and Christian, based on fans' demands and some well-known fan favorites.

The "Fifty Shades" trilogy ("Fifty Shades of Grey," "Fifty Shades Darker," "Fifty Shades Freed"), written by bestselling author E.L. James, tells the story of 22-year-old recent college grad Anastasia Steele, who enters into a dominant/submissive sexual relationship with 27-year old sexy billionaire Christian Grey, and both explore Christian's world of BDSM while trying to understand their complicated relationship.

Here are the couples in no particular order:

Kristen Stewart, 22 and Robert Pattinson, 26

These two stars are a couple in a real life (or was) and have gained extreme popularity with starring as Bella and Edward in "The Twilight Saga" films. James' characters Ana and Christian were based off Bella and Edward, so it's natural that fans want Stewart and Pattinson to play the crucial roles.

According to Gather Celebs, one fan made a video that could be a "Fifty Shades" trailer starring the two "Twilight" stars.

"The video is described on fan sites as 'based on the story Master of the Universe, by Snowqueens Icedragon, subsequently published as the bestselling trilogy 50 Shades of Grey by E.L. James.'" Gather wrote.

The video is shot and black and white. There are scenes from the original "Twilight" films, where Pattinson and Stewart star as Edward and Bella. There are a series of close-ups, followed by the make out scene in the first "Twilight" film. The words "pleasure" and "pain" flash across the screen in red letters, and the letters "S E X" come across the video as well. Pattinson and Stewart are shot with various screen shots which show smiling, sneering, brooding, and sexiness.

Stewart admitted that she was reading the book. Pattinson said that he would lick the pages.

Christian Bale, 38 and Emilia Clarke, 25

Although these two might seem like an odd couple, they might not be.

"The Dark Knight" star had gained a lot of "Fifty Shades" fans based on his role in popular movies. Some say he might be a little too old for the part, but he certaintly fits the description of Grey in terms of darkness. A recent Facebook poll, for The Periscope Post, found Bale as the favorite to play Christian Grey with 33% of the vote (followed by Robert Pattinson with 17% and Gosling with 14% of the vote).

According to Cole at B&R, Bale is known for the radical physical transformations he can endure from one part to the next ("The Machinist," "The Dark Knight,"), and the actor previously played a very similar role to Christian Grey in the 2000 adaptation of Bret Easton Ellis' novel "American Psycho" -- where Bale played Patrick Bateman, a Wall Street investment banker with a serial killer's instincts.

Clarke, on the other hand, is in for the role based on her character in "Games of Thrones," where she plays Daenerys Targaryan.

TheStir.CafeMom.com said that casting Clarke would be a great idea:

"The 25-year-old actress, who's a natural brunette, definitely has the right look. She's both innocent and sweet yet has the potential to be extremely badass. And speaking of asses, she has absolutely no problem with nudity, as she had multiple sex scenes with her on-screen husband. Needless to say, her body is smokin'!"

Gather Entertainment also described Clarke as "intriguing" and that she might be a better fit for the role because of her experience with darker themes explored in "Games of Thrones."

"The naturally brunette beauty has done nude scenes on the show; she's the right age for the role; and her face seems perfect for the part - at times she can look a bit awkward and silly, but she can also look rather sensual."

Alexandra Daddario, 26 and Ian Somerhalder, 33

These two stars are very popular to team up to play the role of Ana and Christian.

Daddario has recently become a fan favorite and is currently winning a poll against rivals Alexis Bledel and Emilia Clarke.

The "Percy Jackson & the Olympians" star has blue eyes, maybe too big for her face, which is the description of Ana in the books.

The actress was featured on Radar Online's "5 Faves for '50 Shades of Grey'" list to play Anastasia Steele. The website said, "The Percy Jackson starlet nails Ana's mix of innocence and curiosity."

Daddario is also pinned on Pinterest as a popular choice for the role. One viewer said, "Her + Matt Bomer is perfect!"

One Books & Review commenter said, "I think Alexandra Daddario is the perfect Ana. She has the long brown hair, alabaster skin, blue eyes too big for her face & pouty lips. She has an innocent beauty requiring no makeup & can be played up sexy when need be."

Somerhalder has been a fan favorite ever since the talk of the "Fifty Shades" movie started.

Somerhalder, who plays Damon on the sexy "The Vampire Diaries" show, has been showing that he wants to play the role of 27-year-old Christian. Last month, he even held a sort of campaign on his Twitter, making it clear that he's more than qualified to take the role, according to The Hollywood Gossip.

It was recently reported that he was meeting with "Fifty Shades" people in L.A. to talk about his role. He revealed this information to his fans at "The Vampire Diaries" Convention in New Jersey.

His acting on "The Vampire Diaries" may be enough for him to land the role of Christian.

Fans are dying for him to be the one. One commenter said, "Definitely Somerhalder! The way he plays Damon on the Vampire Diaries just makes him perfect for the part. He can do hot and cold easily, those grey eyes, that mischievous smile! He is very good at being cold and dominant whilst also being sensitive and caring at times." Another said, "Only Ian Somerhalder can pull off that look of Christian Grey!"

Matt Bomer, 34 and Alexis Bledel, 30

This is a fairly popular couple in the "Fifty Shades" world.

"Gilmore Girls" star Bledel may have the innocence that is needed to pull of the role of Ana.

This actress recently acknowledged her fans on Twitter who want her to play Ana.

"I see that lots of you wants me to play "Ana" in Fifty Shades of Grey. :)," Bledel wrote on her Twitter page. She won a past B&R poll, and is a big fan favorite.

Although some might say she is too old for the role, many think she is perfect.

FansShare describe Bledel with "seductive blue eyes and a stance that binds awkward charm and sex appeal."

"The way Alexis enunciates and expresses herself is also not far from the way intelligent literature graduate Anastasia carries regular conversations."

Movie Pilot describes Bledel as a "spot on" resemblance to Anastasia, who has big blue eyes. "Not only is Bledel cute as pie, but she has Ana's sweet and innocent look down pat," Movie Pilot said. "She looks like she can blush and chew her bottom lip with the best of them at the sight of sexy Christian, so we don't care that she's actually 30 years old (if you can believe it). She's our girl!"

Bomer has always been in the Christian Grey race. He stars as Neal Caffrey in "White Collar" and fans are drooling over him. His role in "Magic Mike" also boost his fan base for him to play Christian.

A debate sparked that he should not be cast as Christian because he is openly gay.

Bret Easton Ellis, who discarded Bomer to play the much coveted role.

Ellis criticized Bomer as a possibility for Christian because Bomer is gay, saying that it "complicates the role" and "it's about an intensely straight actor wanting absolutely to screw Ana Steele."

One commenter said, "Yes Henry Cavil is a good choice but have you seen Matt Bomer. He is my Christian Grey." Another said, "Before I knew they were making a movie, it was too easy to automatically picture Matt Bomer as Christian... He has a very natural seductive look, incredible body, and would probably exceed the expectations of everyone on how Christian Grey is portrayed."

Henry Cavill, 29 and Ashley Greene, 25

Only four years apart, this couple might be a fan favorite to play Ana and Christian.

Greene recently said that she read the steamy "Fifty Shades" books.

"I feel like I kind of had to, it's now pop culture and they're making it into a film. I'm not finished with all of them, but I'm on the third book."

According to the Examiner, the "Twilight" actress could definitely play the part.

"Greene certainly has the beautiful, wide-eyed looks and innocent nature needed for the part," the website said.

One Books & Review commenter said, "Ashley Greene is definitely the on to play Anastasia...I am so surprised they have not found her yet."

She recently became a fan favorite and is gaining momentum on the current Ana poll.

Cavill has always been on the Christian Grey fan list. He played Theseus in "Immortals" and will star as Clark Kent in upcoming movie "Man of Steel."

He regained the lead in the race to play the sexy billionaire by showing off his sexiness in a 2008 cologne commercial that features "Superman" as a sharply dressed Christian Grey-to be about to board a helicopter emblazoned with a letter "G," according to Policy Mic. They have also started a Pinterest page, "Henry Cavill (Christian Grey)," where they post pictures of Cavill resembling Grey's poses and demeanor.

Cavill was also the inspiration behind Edward Cullen from Stephanie Meyer's "The Twilight Saga." Christian Grey's character was inspired by Edward Cullen. James first wrote "Fifty Shades of Grey" as Twilight fan-fiction.

Fans are screaming for him. One commenter said, "Henry Cavill is pure perfection." Another simply said, " HENRY CAVILL IS PERFECT!! HE IS CHRISTIAN GREY! Oh my Fifty!!"

Alexander Skarsgard, 35 and Lucy Hale, 23

Hale has read the "Fifty Shades" books, and she also hinted that she would be up for a role like Anastasia.

"I definitely am ready to take a step and do something a bit more risky, absolutely, but it's a fine line," she told MTV News. "I don't know what that fine line is, but I'm definitely ready to explore a darker side of my acting abilities."

"I'm definitely ready to explore a darker side," she said of her acting career, according tocelebs.gather.com. She said she's ready to do something a "little more risky."

MTV News also talked to the "Pretty Little Liars" star earlier in the year about the fan support for her landing the leading role in the movie. "People have said that, but people have also said [I could play] the little sister, which I think could make sense, because I look a little young for Ana, but God, what a big role to take on," she said. "I'm really curious to see how it's all going to [play out]."

Books & Review fans also agreed she could play Anastasia. One commenter said, "I could definitely see Lucy as Ana. She has to be young, naive, demure. I see it definitely."

Skarsgard has been on the list from the beginning. At Comic-Con San Diego 2012, he revealed to fans that he hasn't read the book nor has he been offered a casting part.

The "True Blood" star recently appeared in a short advertisement for Calvin Klein's latest fragrance, "Encounter."

According to Business Insider, the ad was inflencued by "Fifty Shades of Grey."

"There's little doubt the new ad wasn't influenced by the latest phenomenon considering how close the short film attempts to mirror elements of James' novel. Even the ad's dark blue and grey tones bear a striking resemblance to the covers of the "50SoG" novels," Business Insider said.

There's even focus of Skarsgard riding up an elevator - an imperative place of interest for the book-to the home shrouded in glass windows.

Gather Entertainment said that Skarsgard "oozed sex appeal" in the ad and that it would be hard to imagine other actors capable of smoldering the way he does.

Maybe raving fans could change the producer's minds.

One commenter said, "I only picture Alexander Skarsgard as Christian. I saw him as it the first time I read it." Another said, "I agree Alexander is the one and only Mr. Grey. He has sexuality and a presence on screen that just comes natural. For me, there is no one else. Give him the script already!" Another said, "Alexander Skarsgrad, has the perfect fit for the role. He could easy be a Dom (of course he could be mine). He is very thing that El.James describe for Christian. I see it everytime I read the books."

So "Fifty Shades" fans, which couple would you want to play Ana and Christian? VOTE NOW!

Click HERE to see who the front-runners are this week for Christian and Ana.

Click HERE to vote for Anastasia Steele!

Click HERE to vote for Christian Grey!