Fugitive Unknown

The free terraforming bonus you get with neutral has a... profound effect on the game. It can easily turn those 3-6 planets into class 10-20 powerhouses once you've got the tech and does it instantly, the only cost is to research the tech. It's definately not to be underestimated.

There are a few abilities I really really like. I think my favorites are economy, population growth, diplomacy and morale, in that order.