In order. 1. I would say the Fallen, they had a society built around scavenging and conquering which wasn't too bad til the Traveler abandoned them to die. 2. The Cabal seem to mindless care about war and conquest which cost them there homeworld to Xivu Arath, Caiatl is quite intelligent and tactful. 3. The Hive made a dumb decision with the initial Big Three costing them a big betrayal to the Darkness. Only the Big Three seem to have any manner of intelligence the rest are like mindless bugs that are like "Rawr, must kill, smack with big sword, sword-logic, rawr." [spoiler]The Vex are a wild card, they have quite a lot they do in the background and we don't know what they plan to do. I don't think The Traveler or Witness knows what the Vex's purpose or plan is. The Vex are the scary Matrix robots that came from a simulation. [/spoiler]