While running and grinding through FFX HD on Vita, I started thinking about the personalities of these characters and started imagining what they would look like in a movie. Let me know what you think of my choices or if you have an better suggestions or additions to the cast.
Note: There are a LOT of characters in this game, and many of them have minor roles. I'll start by only naming major characters and make an effort at adding minor characters if the thread continues to develop.
From left to right: Auron, Yuna, Wakka, Lulu, Tidus, and Kimahri
Auron: Based primarily on his looks, but secondarily on how much I don't like this actor when he speaks, I'm going to give this mostly silent character to Christian Slater.
Yuna: While I don't think she looks a whole lot like the character in the game, I definitely think that Emma Watson has a calm and youthful enough demeanor to take on the role of Yuna.
Wakka: I had a lot of trouble with this one, but I think casting Bruno Mars as Wakka would be hilarious. Plus, I wouldn't mind seeing this guy trying to suck at Blitzball.
Lulu: If you've ever played this game, you know that Lulu is a cold hearted woman with a resting bitch face and dark sense of humor. After watching Black Sails for a while, I'm going to go with Jessica Parker Kennedy.
Tidus: Also a difficult match for me to pick, but I started thinking about what guy could be as obliviously animated and still be strong enough to command leadership in the midst of an odd turmoil. I decided to go with J-rock musician Miyavi for his androgynous look and wild personality.
Kimahri: Kimahri is a runt among an ancient race of warrior beast-people. However, I would have no problem with Dwayne Johnson donning fur, teeth, and a polearm to defeat enemies for a greater good.
Rikku: This isn't hard. You need a girl with a friendly personality and a costume to play Rikku. While I don't know if she has any acting chops or not, Jessica Nigri IS Rikku.
Note: There are a LOT of characters in this game, and many of them have minor roles. I'll start by only naming major characters and make an effort at adding minor characters if the thread continues to develop.

From left to right: Auron, Yuna, Wakka, Lulu, Tidus, and Kimahri

Auron: Based primarily on his looks, but secondarily on how much I don't like this actor when he speaks, I'm going to give this mostly silent character to Christian Slater.

Yuna: While I don't think she looks a whole lot like the character in the game, I definitely think that Emma Watson has a calm and youthful enough demeanor to take on the role of Yuna.

Wakka: I had a lot of trouble with this one, but I think casting Bruno Mars as Wakka would be hilarious. Plus, I wouldn't mind seeing this guy trying to suck at Blitzball.

Lulu: If you've ever played this game, you know that Lulu is a cold hearted woman with a resting bitch face and dark sense of humor. After watching Black Sails for a while, I'm going to go with Jessica Parker Kennedy.

Tidus: Also a difficult match for me to pick, but I started thinking about what guy could be as obliviously animated and still be strong enough to command leadership in the midst of an odd turmoil. I decided to go with J-rock musician Miyavi for his androgynous look and wild personality.

Kimahri: Kimahri is a runt among an ancient race of warrior beast-people. However, I would have no problem with Dwayne Johnson donning fur, teeth, and a polearm to defeat enemies for a greater good.

Rikku: This isn't hard. You need a girl with a friendly personality and a costume to play Rikku. While I don't know if she has any acting chops or not, Jessica Nigri IS Rikku.