Jack is definetley at his best when he is as cool as a cutecumber. Like when he was talking with Sloane and he knew that a sniper s aiming at his head. He had the full 'Poker face' Vicktor Garber just excells at that sort of thing.
Every time I see this thread my mind goes yelling: "how do I like Jack best? Cooked."
Eerr. anyway, my vote went to 'Thawing Jack' because as much as I enjoy the action-hero Jack and cool Jack and all the other Jacks there is I find myself more often enjoying the moments where we can see a flashes of what he used to be. They make me wonder I guess.