Fans have been wondering who will play Christian Grey and Anastasia Steele in "Fifty Shades of Grey."

These two roles are key to the movie. However, there are other supporting roles that are important to cast as well.

The steamy "Fifty Shades" trilogy ("Fifty Shades of Grey," "Fifty Shades Darker" and "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 the world of BDSM while also trying to figure out their relationship.

Many fans already know who they want to play Elliot Grey and Katherine Kavanagh.

Elliot is Christian's brother and owner of Grey construction. Kate is Anastasia's tenacious best friend. Both come together in the books (and eventually get married.)

On Twitter, @Mr_Elliot_Grey page features "Magic Mike" star Alex Pettyfer as Elliot. Pettyfer was recently considered for the role of Christian, though many fans think he would be better as Elliot. There is also a Facebook page dedicated to Pettyfer as Elliot.

On another Twitter account, @ElliotCoolGrey, actor Ryan Reynolds is featured as Elliot.

As for Kate, many fans think "Savages" actress Blake Lively should play Anastasia's best friend and roommate.

There is a Twitter page, @KateK_Grey, that features Lively as the role of Kate. The account tweets to @ElliotCoolGrey, saying that they are a couple.

"Arrow" actress Katie Cassidy was linked to the role of Kate. She also starred in "Supernatural" and "Gossip Girl." A Tumblr account, "Fifty Shades of Grey Cast," also features Cassidy as Kate.

One Books & Review commenter said, "I can see Katie playing the part of Kate."

The Business Insider, however, had a different actress.

Amber Heard won a poll for to play Kate.

As for Christian and Ana, many names are being thrown out there.

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

"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.

"Man of Steel" star Henry Cavill looked extremely sexy in a 2008 cologne commercial that features him sharply dressed as a Christian Grey-to-be about to board a helicopter emblazoned with a letter "G," according to Policy Mic. Cavill fans have also started a Pinterest page, "Henry Cavill (Christian Grey)," where they post pictures of Cavill resembling Grey's poses and demeanor.

Among fan favorites are "The Vampire Diaries" star Ian Somerhalder, Colin Egglesfield, Jessie Pavelka, and "White Collar" Matt Bomer.

What do you think about Pettyfer and Lively as Elliot and Kate? Share your thoughts below!

Click HERE to vote on the newest Anastasia Steele poll!

Click HERE to vote for Christian Grey!

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