The first one is definently the best imho.
It's clean and simple, the way a sig SHOULD be. If you get too much crap going on it takes from your render and just becomes a design.
Number 1 is actually really good, you were able to keep it simple while still making it snazzy and awesome. 10/10
3- Too much going on, not clear enough, the sig became too busy.
4- Better than 3, but I personally have a distaste for it. (I'm an anti-Scorpion person for more than the usual reasons. Yellow being my least favourite colour has a horrible impact on that harpooning loser. Hated the guy from MK 1)