Only three civilizations for Starcraft!? This needs some serious work from a Starcraft Junkie like myself
Terran Civilizations
Kel-Morian Combine:
Leader: Gen Mah Sakai
Color: Green
Unique Unit: Improved SCV (this civ was known for its excellent skills in gathering resources)
Sons of Korhal:
Leaders: Angus Mengsk, Arcturus Mengsk
Color: Not Sure
Unique Unit: A lot of different ideas I have, I can't really decide on just one at the moment
Terran Confederacy:
Leader: Edmund Duke
Color: White (its the color of Alpha Squadron, but its their most important Squadron)
Unique Unit: Alpha Commando (improved Marine) or Assassin (improved Ghost)
Umojan Protectorate
Leader: Minister Jorgensen
Color: No Idea
Unique Unit: No idea
United Earth Directorate:
Leaders: Admiral DuGalle, Vice Admiral Stukov
Color: No Idea
Unique Unit: Nurse (improved Medic, since Medics were the UED's specialty unit)
Zerg Civilizations
Garm Brood:
Leader: Cerebrate Zasz
Color: Orange
Unique Unit: No Idea
Jormungand Brood:
Leader: Cerebrate Araq, Kerrigan*
Color: Purple
Unique Unit: Some kind of cheaper Zergling, since this brood was all about numbers
Surtur Brood:
Leader: Cerebrate Kagg
Color: Blue
Unique Unit: No Idea
Tiamat Brood:
Leader: Cerebrate Daggoth, The Overmind**
Color: Red
Unique Unit: Hunter Killer (improved Hydralisk)
*
Kerrigan was infested by this Brood, and in the campaign you play as this Brood, coincidentally playing Kerrigan (thats why she is a leader for the Jormungand Brood)
**
The Tiamat Brood's purpose is to protect the Overmind. Not only that, but they're the biggest Brood. That is why the Overmind is a leader for this Brood
I know that the Zerg was for the most part one large civilization, but when the Overmind was killed, disorder did come between the Broods.
Protoss Civilizations
Dark Templar:
Leaders: Matriarch Raszagal, Zeratul
Color: Not Sure
Unique Units: Dark Templar, Dark Archon
High Templar:
Leaders: Judicator Aldaris, Tassadar
Color: Not Sure
Unique Units: High Templar, Archon
The High Templar could actually be split up into the three Castes: Judicator, Khalai, and Templar, so I might change that
Other
Raynor's Raiders: (A mix between Terran and Protoss units)
Leaders: Jim Raynor, Fenix
Color: Not sure
Unique Unit: Raider (an improved Vulture)
You COULD possibley have the Samir Duran's Hybrids (beings with the essence of a Zerg and the form of a Protoss) if you all are up to the challenge. In my opinion, I'd LOVE to see a Hybrid Civilization
Barbarian Ideas:
Two words: Pirate Militias. There were quite a few different ones in the Koprulu Sector. In my opinion, they're your best bet for Barbarians