Since most of what I typed (on phone mind you!) was deleted when the page reloaded for no reason, I'm only going to write my Fancast, until later.
The Flash/Barry Allen-Beck Bennet
Yes, The guy from the att commercials with the kids. He can pull off a sense of deadpan seriousness that would work well with Barry the serious science nerd. Just dye his hair blonde.
Iris West Allen-Bridget Regan or Bryce Dallas Howard
Barry's faithful wife, who met him by being a pesky and annoying version of Lois Lane. She fully supports his role as The Flash, but questions how he can still always be late to their dates
James Forrest-Anthony Anderson
Barry's funny fat black friend. He knows that Barry is the Flash, and was the one who designed his costume for him.
Captain Frye-Bruce Greenwood
An old pro Police captain who Barry has known since he was a kid. He has a combative relationship with Singh, as he is a gung ho gun toting cop, who Singh feels is always mucking around with crime scenes and evidence.
An asshole Indian who is Barry's boss. Makes J. Jonah Jameson look like Aunt May.
Captain Cold-Sean Bean
A blue collar crook who wants to keep it that way. Constantly beaten by the Flash, he surmises that powers will help him and the Rogues pull off heist better and protect them from the Flash. Raised by strict (dead) parents, he has very tight rules for the other Rogues, and confronts Trickster on his booty magazines, Heatwave's drug use, and Top's dirty comments towards his sister, who he is overprotective of.
The Top-Liev Schreiber
A womanizing smooth talker, he feels that the Rogues should evolve past simple robberies. He has a highly physical relationship with Golden Glider, which Cold strongly disapproves of.
Golden Glider-Saoirse Ronan
A beautiful ice skater who has fallen in love with a bad boy. She goes with The Top when the Rogues desert Cold, but wishes that her boyfriend and her brother would get along, especially when they begin a war for Central City.
Heatwave-John Tuturro (sp?)
Heatwave has an obsession with fire like a policeman might have with justice. His aversion to cold always put him at odds with its Captain, and he further resents Cold for experimenting on the Rogues, as he felt that this was the cause of their breakup. Cold questions that it he is so just and chivalrous, he wouldn't do drugs. Heat Wave responds....."Um...simply applying Lady Flame to nature. And when the two make love....there are some effects".
The Trickster-Jesse Eisenberg
A bored kid from the suburbs, he leaves before getting powers. Later, he helps Flash and Cold track down the Rogues. He is essentially a Rob Liefeld/Michael Bay hybrid, always talking about EXTREME gadgets and blowing stuff up.
Barry's coworker who harbors feelings for him, despite his marriage to Iris.
Captain Boomerang and Weather Wizard appear, but after the experiment to get powers goes awry, they desert Cold, leaving for a sequel.