I agree with @joannekwan.
The intensity of the torso in no.2 takes too much away from the face (which is supposed to be the highlight of a character). No. 3 is pretty nice too, since the first thing you see is his face, but I think it looks a little too...assassin-esque? Unless that's the look you're aiming for...
In my opinion, no.4 looks a little too bland and flat. It doesn't have any interesting texture whatsoever.