Here is a list of characters from the show that I compiled.
If there are any inaccuracies or mispellings, please let me know.
Also if I left anybody out, please mention, and I will add them to the list.


MAIN CHARACTERS
Kara "Starbuck" Thrace [CAG]
William Adama [Admiral]
Saul Tigh [Executive Officer]
Lee "Apollo" Adama [Commander]
Aaron Kelly [Landing Signals Officer]
Anastasia "Dee" Dualla [Communications Officer]
Felix Gaeta [Tactical Officer]
Laura Rosin [President]
Tom Zarek [Vice President]
Tory Foster [Secretary]
Gaius Baltar [Scientist]
Galen Tyrol [Deck Chief]
Cally Tyrol [Deck Specialist]
Sharon "Athena" Agathon 8 (Cylon) [Raptor Pilot]
Karl "Helo" Agathon [Raptor Pilot]
Samuel T. Anders [Militia Leader]
Doctor Cottle [Surgeon]
Hera Agathon [Helo's and Athena's baby]
Nicholas Tyrol [Galen and Cally's baby]

Billy Keikeya (Dead) [Secretary. Killed during a hostage crisis.]
Ellen Tigh (Dead) [Wife of Saul Tigh. Murdered by Saul tigh on New Caprica.]
Zachary Adama (Dead) [Youngest son of William Adama. Fiance of Starbuck. Died during Viper pilot training.]


SUPPORTING CHARACTERS
Louanne "Kat" Katraine [Viper Pilot]
Brendan "Hot Dog" Costanza [Viper Pilot]
Margaret "Racetrack" Edmondson [Raptor Pilot]
Seelix [Deck Specialist]
Gunnery Sergeant Mathias [Marine]
Charlie Connor [Marine]
Jean Barolay [Milita Soldier]
Sarah Porter [Geminon Representative]
Marshall Bagot [Virgon Representative]
Phelan [Mob Kingpin]

Boxey [Child]
Kasey [Child]
Julia [Kasey's Mother]
Sergeant Hadrian [Master at Arms]
Corporal Venner
Cole "Stinger" Taylor [Former Pegasus CAG]
Noel "Narcho" Allison [Former Pegasus Pilot]


[B]DEAD
Tucker "Duck" Clellan (Dead) [Viper pilot. Suicide bombed police initiation on New Caprica.]
Nora Clellan (Dead) [Viper pilot. Tucker's wife. Died on New Caprica.]
Alex "Crashdown" Quartararo (Dead) [Raptor Pilot. Died on Kobol.]
James "Jammer" Lyman (Dead) [Deck Specialist. Paricipated in New Caprica exodus. Killed by Secret Jury.]
Socinus (Dead) [Deck Specialist. Died on Kobol.]
Tarn (Dead) [Soldier. Died on Kobol.]
Elosha (Dead) [Priest. Died on Kobol.]
Maya (Dead) [Hera's adopted mother. Died on Kobol.]
Sue-Shaun (Dead) [Militia Soldier. Murdered by Starbuck at hospital on Caprica.]

Richard Adar (Dead) [President of the 12 Colonies. Died during Cylon invasion.]
Helena Cain (Dead) [Admiral Pegasus. Killed by Gina 6.]
Jack Fisk (Dead) [Executive Officer Pegasus. Killed by mobsters.]
Barry Garner (Dead) [Executive Officer Pegasus. Killed during Cylon attack of Pegasus.]


CYLONS
Leoben Conoy X
Simon X
Brother Cavil X
Number 3
Danna Biers 3
Number 5
Aaron Doral 5
Number 6
Caprica 6
Gina 6
Shelly Godfrey 6
Number 8
Sharon "Boomer" Valerii 8

You forgot Hera. Also that black gangster and the older doctor/Cylon traitor

Boomer and Athena are separate characters of Sharon. Not to mention the other Eights.

"Al from QL" is Brother Cavil (a #2)
The Threes, played by Lucy Lawless first appeared as D'Anna Biers
The Fives are played by Matthew Bennett
Leoben Conoy is the skin-job that tries to convince Starbuck to love him
Simon is the Cylon that treats Starbuck's gunshot wound, pretending to be human when she goes to Caprica
Helena Cain - the Pegasus captain played by Michelle Forbes

Updated.