Alkari
Ship Defence: +50, Artifacts Home World (Increases the amount of research that the homeworld can put out).
Bulrathi
Ship Offense: +20, Ground Combat: +10, High Gravity Homeworld (Most of the productive planets are high gravity, so this is pretty damn awesome).
Darlocks
Espionage: +20, Stealth Ships (Our ships can't be seen on the overworld map. Probably only good against humans, to be honest).
Elerians
Ship Defense: +25, Ship Offense: +20, Telepathic (MIND CONTROL,
and bonus to espionage/diplomacy), Omniscient (Can see all ships/colonies/planets on the world map).
Gnolams
Tax: +1, Low Gravity (Low gravity planets are small, crappy and rare, so this is a negative trait), Expert Traders (More money from trade agreements, producing food/trade goods, though honestly it's less than you think), Lucky ('Better' random events).
Humans
Charismatic (
Better relationships with the AI AI will hate our guts anyways, but at least we can assimilate captured planets faster).
Klackons
Food Production: +1, Industrial Production: +1, Large Home World (We get to fit more people on our homeworld, which is always a good thing), Uncreative (Probably the worse trait in the entire game as it messes with our research in the worse way possible, though it can be countered with lots of spies, trading and warmongering).
Meklars
Industrial Production: +2, Cybernetic (Uses industry to partly feed colonists, which is more harmful than useful; Makes ships repair themselves in battle).
Mrrshan
Ship Offense: +50, Rich Home World (More minerals on your homeworld, which is always a good thing), Warlord (More experience and command points, allowing us to field a larger and better fleet).
Psilons
Scientific Research: +2, Low Gravity (Low gravity planets are small, crappy and rare, so this is a negative trait), Artifacts Home World (Increases the amount of research that the homeworld can put out), Creative (Best research trait in the game, as it gives us all of the research).
Sakkra
Population Growth: +100, Food Production: +1, Espionage: -10, Subterranean (Allows us to stuff more folks onto a planet, and helps when defending colonies), Large Home World (We get to fit more people on our homeworld, which is always a good thing).
Silicoids
Population Growth: -50, Lithovore (We eat rocks, so we don't have to waste population farming), Repulsive (Significantly reduces our diplomacy choices in a game where the AI hates us, though it will take us longer to assimilate captured colonies), Tolerant (Best industrial trait, since we ignore the biggest production stopper, pollution, while increasing the amount of people a planet can support at the same time).
Trilarians
Aquatic (Basically makes certain types of planets more habitable to us, which could be a big boon if we go with Abundant Organics), Trans Dimensional (Allows our ships to travel faster on the overhead map and in combat, and also gives us protection against a random event that'll only appear once; We can build ships earlier if we go with Pre-Warp technology levels).
Additionally each race has one of four government types. Since I don't feel like repeating myself, I'll list them all here.
DictatorshipThe most common government type in the game. Alkari, Bulrathi, Darlocks, Gnolams, Meklars, Mrrshan, Psilons, Silicoids, and Trilarians all have this government type. That's nine out of thirteen! Obviously Dictatorship is the default government, and it's only advantage is to increase defensive espionage by 10%. Also colonies get -20% morale until you built a barracks, but that's more annoying than anything else. Losing our capital also has additional negative moral effects until we build a new one, but in that case we probably couldn't recover anyways, so who cares?
FeudalismSecond most common government, with both Elerians and Sakkra having this. On the one hand ships are a third less expensive to build. On the other hand research is halved, which is quite crippling and makes the Elerians and Sakkra worse choices. Also Feudal governments still have to worry about barracks and capitals like Dictatorships.
DemocracyOnly humans get to enjoy this government choice. Research and income is boosted by 50%, captured colonies assimilate faster, and we get more out of trade/research agreements. With the additional assimilation bonus from Charismatic, humans get to quickly convert captured colonies and make them their own, and the extra research will help them conquer those colonies. Democracies also have -10% to defensive espionage, but it's not that bad. While Democracies no longer have to worry about building barracks, losing the capital is still a bad thing.
UnificationA government type that increases production and farming by 50%, and defensive espionage gets +15%. Also Unification governments don't have to worry about losing their capital, since their colonies don't care about morale, which is a bit of a mixed blessing. The only downside to Unification is that it takes much longer to assimilate enemy populations, assuming we didn't nuke them from orbit in the first place. The Klackons get Unification, though its bonuses are still overshadowed by Uncreative.