I really like your second two. That's a good style to shoot for. I've always wanted to give my sig's a "glow" type look, but never really bothered to try it.
Also, If your posting to make people sig's, I would have an admin move this thread to "Request Art".
If its just to show off your amazing skills, It's in the right spot then, and i applaud your effort on making fine artwork. Keep it up!