*Off Topic*
Some of you guys that are giving your crits are being to harsh, Not to mention when we look at your sigs it shows that you have no experience in what your talking about.
*On Topic*
Out of all 3 I would have to say that your 2nd sig (the purple one) has to be best overall. The other 2 are good but I dont like the grunge you added, I can understand with the 1st but the 3rd kind of looks strange? I dont know, Hard to crit with 3d render with grunge.
*Edit*
I just noticed in your 2nd sig (the purple one) that the chick is poorly cut out, Around the hat area. Its either bad cutting or just the background giving it that effect, Not sure which.
Lay-Ter