Sorry there are no pictures for this as that would take a lot of time to do but here is a list of people I think would work great in an appearance in the TV show 24.
These are broken up into sections to help people if necessary.
President:
Liam Neeson
Aaron Eckhart
Lawrence Fishburne
Robert Downey Jr.
Michael Keaton
Harrison Ford
Denzel Washington
Gary Oldman
Kevin Costner
Gene Hackman
Tom Hanks
Danny Glover
Samuel L. Jackson
William H. Macy
Mark Hamill
Helen Mirren
Kurt Russell
Matthew McConaughey
Bruce Willis
Brian Cox
Edward Norton
Mel Gibson
George Clooney
Don Cheadle
Jim Caviezel
Vice President:
Tommy Lee Jones
Steve Zahn
Helen Mirren
Presidents Staff:
Chris Evans
Jennifer Lawrence
Nicole Kidman
Michelle Pfieffer
Julia Roberts
Helen Mirren
Brendan Fraser
Tim Roth
Natalie Portman
Steve Carrell
Liv Tyler
Kiera Knightley
Secret Service Agents or Heads:
Aaron Eckhart
Dwayne Johnson
Vin Diesel
Chris Pine
Will Smith
Hugh Jackman
Gerard Butler
Tom Hardy
Joseph Gordon Levitt
Leonardo Dicaprio
Mark Wahlberg
Sean Bean
James McAvoy
Sam Worthington
Daniel Craig
Michael Fassbender
Benedict Cumberbatch
Michael Shannon
Don Cheadle
Tom Cruise
Tobey Maguire
Terrance Howard
James Franco
Karl Urban
Tim Roth
Michael Pena
Ryan Gosling
Josh Brolin
Christian Bale
Military
Bruce Willis
Dwayne Johnson
Liam Neeson
Chris Pine
Anna Popplewell
Zoe Saldana
Russell Crowe
Sean Bean
Tobey Maguire
Tim Roth
Josh Brolin
Aaron Eckhart
Christian Bale
CTU Agents or Heads:
Lawrence Fishburne
Cuba Gooding Jr.
Dwayne Johnson
Amy Adams
Scarlett Johansson
Chris Pine
Zoe Saldana
Daniel Radcliffe
Michael Keaton
Ben Affleck
Matt Damon
Will Smith
Anna Popplewell
Tom Hardy
Joseph Gordon Levitt
Russell Crowe
Ellen Page
Jennifer Lawrence
Emma Stone
Chris Cooper
Leonardo Dicaprio
Mark Wahlberg
Kevin Costner
Jack Black
Orlando Bloom
James McAvoy
Sam Worthington
Gemma Arterton
Ralph Fiennes
Samuel L. Jackson
Tobey Maguire
James Franco
Jake Gyllenhaal
Katie Holmes
Michelle Monaghan
Rachel McAdams
Bradley Cooper
Karl Urban
Matthew McConaughey
Ryan Gosling
Jessica Biel
Jeff Daniels
Alan Arkin
Liv Tyler
Dakota Fanning
Police:
Dwayne Johnson
Vin Diesel
Scarlett Johansson
John Cusack
Ewan McGregor
Patrick Warburton
Anne Hathaway
Jessica Biel
Katie Holmes
Bradley Cooper
Eddie Murphy
Gerard Butler
Christian Bale
Villains:
Liam Neeson
Hugo Weaving
Sylvester Stallone
Cuba Gooding Jr.
Amy Adams
Zoe Saldana
Robin Williams
Angelina Jolie
Hugh Jackman
Christian Bale
Piper Perabo
Charlie Sheen
Mel Gibson
Eric Bana
Gary Oldman
Denzel Washington
Tom Hardy
Joseph Gordon Levitt
Russell Crowe
Chris Cooper
Leonardo Dicaprio
Jack Nicholson
Kevin Costner
Gene Hackman
Johnny Depp
Jude Law
Kevin Spacey
Colin Farrell
Viggo Mortensen
Sean Bean
Ben Kingsley (a real villain)
Benedict Cumberbatch
Michael Shannon
Michael Fassbender
Jim Carrey
Michael Caine
Arnold Schwarzenegger
Uma Thurman
George Clooney
Tommy Lee Jones
Nicole Kidman
Danny DeVito
Michelle Pfeiffer
Cillian Murphy
Morgan Freeman
Julia Roberts
Steve Buscemi
Robert Redford
Thomas Haden Church
Ralph Fiennes
Samuel L. Jackson
Billy Bob Thornton
Sandra Bullock
Jim Belushi
Anne Hathaway
Clive Owen
Jeff Daniels
Christopher Walken
Michelle Monaghan
Katie Holmes
Mark Hamill
Rachel McAdams
Helen Mirren
Brian Cox
Karl Urban
Tim Roth
Edward Norton
William Hurt
Jim Caviezel
Terrance Stamp
Brendan Fraser
Matthew McConaughey
Nicolas Cage
Eddie Murphy
Gerard Butler
Sean Penn
Josh Brolin
Well that's who I have picked. I know a lot of you may disagree with some of these but I thought they would be good. Is there anyone you would want to see that isn't listed? comment below and I'll add them to it!