Probably 3rd or 1st. Although the green vein lookin' things on the guys face (scanner darkly dood?) look a bit off to me. Not keen at all on the last one and the text on the 4th doesn't look right annnd 3rd is a bit boring; unless you traced/drew that yourself?
Can you please send me the link to the stock of sig 4? The colors there were chosen wisely. I love it. Sig 3 and 4 are the best. Three because of the flow and originality. Four because of the colors and stock.