Disgustipated
Deity
You only "need" to get planetary habitability up to 100% - anything else and you're just collecting xp and Nexus points. With five main worlds though, I'd definitely recommend going elsewhere if you get bored (or simply not playing it for a while, of course).
Actually I was under the impression you don't need to get viability to 100% at all. If I play again, I wasn't planning on it. I grew frustrated after not being able to find a way in the Kett base on Eos, there was a force field or something blocking it. I don't have the patience to try and climb mountains looking for a way in. I was hoping that would get me close to 100%. But to be honest, I don't care anymore. Screw these people. Why must I do everything. I'm thawing these colonists out for a reason, time for them to do some work. Seriously if the story were more engrossing, I would be more tempted to finish this game. The boring companions don't help. They are too nice sometimes, I think it would be cool if you had a companion that was in your face and fairly hostile towards you and the choices you make. These companions don't care at all.
I think I chose Miranda for that reason, her posterior isn't nothing to sneeze at as well, perhaps her best asset. As for personality, she mellows out a bit if you romance her. Tali is too young, and how would sex with her even be possible? I suppose you could have a celibate type love, but that would lead to some frustrating evenings in the bathroom taking care of things yourself. But I do love Tali's voice. Give me Tali's voice and personality and Miranda's body.She thought Miranda was a better option because she, and I quote, "has the best boobs".