For me it would definitely have to be Director Tann... for someone trying to bring the prominent species of the Milky Way to a new galaxy, its pretty asinine that he's very forward about his racism to Krogans. I'm surprised he was in line to be a director...did they not put these candidates through psych evaluations? I'm pretty sure "not particular fond of an entire race" would be a disqualifying factor.
After him, SAM. He's basically Navi, only an AI supercomputer embedded into your very being instead of a floating fairy. Sure, SAM. Tell me again about how I can find minerals. Its not like we've done this dozens of times before. Just swap out "Hey! Listen!" with "Pathfinder..." and you pretty much have a robo-fairy your dad slipped into your ear while you begged for oxygen.