Evil --
Immediate bonuses, of which perhaps the strongest is +PQ -- I've seen +40-50% PQ, which is huge. Of course, you also take a huge morality hit for choosing that path, compared to, say, a mere +1 morality for declining a starship bonus.
Long-term: Additional bonuses to soldiering, production, economy, cultural resistance, and seemingly diplomacy with evil factions.
Good --
No immediate bonuses. Long-term includes better relations with good nations, more trade routes (but still limited to 10), trade centers (yes; according to GCImps.IMP it's +15% manufacturing, morale, economic, influence, research!), more influence and diplomacy IIRC. There is no Good trade good, if memory serves (evil gets Artificial Slaves) but it does have a wonder -- the Trade Monument (+20% trade income) to stack against the Life Force Power (+25% economy). Also, good races are less likely to suffer much from Fundamentalist revolts.
So far, on Huge/Normal games I've seen evil races research evil techs, but I haven't seen the good races (except my Terrans when I'm playing good) reach the good techs.