It would make the most sense to use his look from Jak 3 since that is the look they used to market him in his most recent game (Move Heroes). I'd rather them use the Jak 2 version though. He looked badass in that one. PLEASE NO JAK X OR LOST FRONTIER!! He looked dumb as hell in those.
Jak 3 because that version looks more mature and had more abilities. It wouldn't seem right seeing the Jak 2 version using Light Jak powers or seeing the original Jak use either Light or Dark powers. --- I am the Box Ghost. Beware. http://25.media.tumblr.com/tumblr_lqz6jrOvvK1qd3p2to1_500.gif