Human, because they are adaptive and well-balanced(I always play humans in D&D for the same reasons)and more importantly because I am a pro-human xenophobe; if I had the option I honestly would've liked to 'pick' my crew, loaded up the Normandy with humans, like Navigator Presley my bro, and kicked all those aliens out on their asses except for maybe an Elcor or a Hanar, I Tolerate those guys