3. Joseph Gordon-Levitt
Though capable of intimidation and menace, as seen in Looper, JGL is mostly known these days for his boyish good looks and boundless charm. One can imagine him as an improvement on Fassbender's David; an artificial crew member who makes great jokes, fits in with everyone, loses at poker and is gracious about it, and obeys orders without question. Until he finds out he's the android on board... yeah. Then he has the existential crisis and wonders if any of his friends are really capable of being friends with an expensive piece of equipment.
It's an interesting idea, but I'm not sure Levitt would get a chance to use any kind of characterization typical of the androids. The cool, detached confidence that Henriksen used for Bishop would have to go out the window, but the childlike curiosity displayed by all three androids when coming face to face with the xenomorphs and Engineers is something Levitt has in spades.