Here are my basic notes about backgrounds:
Same as written in the True20 Revised Core Book.
+1 Intelligence, -1 Charisma (I was thinking either Charisma or Wisdom, to represent that the Turians are good strategists and technologists but poor intuitive thinkers due to being too rigid)
Bonus Feats: Firearms Training, Attack Focus (due to the compulsory military service), Iron Will. Their autocratic society and military discipline makes the average Turian willful and combative.
Favored Feats: Attack Specialization, Master Plan.
+1 Wisdom, -1 Strength (for balance's sake more than anything, Asari don't seem to be particularly lacking in anything)
Bonus Feats: Lightning Reflexes, Attractive
Bonus Skills: Diplomacy and Sense Motive.
Favored Power: One power chosen off of the Biotic List, which treats the Asari's total hero level as her Adept level for the purposes of that power's power rank and effects.
+1 Constitution, -1 Intelligence
Bonus Feats: Regeneration (Cure power that can only work on self, uses Krogan's total hero level as their Adept level for all purposes), Firearms Training, Improved Strike
Favored Feats: Tough, Stunning Attack
+1 Intelligence, -1 Strength
Bonus Feats: Improved Initiative, Eidetic Memory
Bonus Skills: Two Knowledge skills
Favored Feats: Evasion, Skill Mastery
+1 Intelligence, -1 Constitution
Bonus Feats: Improvised Tools, Dedicated (Toward the Migrant Fleet unless there's a good reason not to be, in that case, as appropriate to the story)
Bonus Skills: Repair, Craft
Favored Feats: Skill Mastery, Favored Opponent (Constructs)
It's been a couple months since I played Mass Effect 2, so I might be forgetting something important, but if I was running a Mass Effect Tabletop game tomorrow, this is what I'd pass out to the players for Background choices.