I like #1 the best. The metallic blue surfaces look really good.
#2 is kind of dark and harder to see against the black background, and the small red, blue, and green parts don't really go well with the rest of the ship which is dark brown. It might be better to make those small parts all red or all green, or perhaps have two colors; with three colors it has a sort of mismatched appearance.
#3 is too pink-looking. Aliens probably have a different sense of aethetics when it comes to colors for their ships, but in my opinion, I wouldn't want to fly a pink ship for the same reason I wouldn't want to drive a pink car.
Very nice work.
