Rachni + morality [ME1]

That was a pretty slick way that the writers used to set this up, as we clearly do not have enough data to make an informed decision and yet we are forced into a black/white choice here. There sure are several ways to justify both choices, but in the end it comes down to the way you see the world and gut feeling (which is probably pretty much the same thing sometimes).  

Me, I´d be all for taking off and nuking the entire site from orbit (it´s the only way to be sure) in certain cases, but this is not one of them. I also perceived this scene as a nod to the novel "Ender´s Game", in which a choice pretty much like this plays a central role. Entirely wiping out an intelligent species was not an option for me (Though I chose the "destroy" ending first, so much for being consistent ), and the choice came basically down to what I personally believe. So this was a pretty good way of forcing me to consider this.

Interesting thing about the companions. I played the game 2 or three times and usually took a combination of Wrex/Garrus/Liara to this mission, so I did not know this. Figures that Ashley would take the opinion opposite to my own .