Dont put outer glow or drop shadows on your render. Makes it look flat. Also just stop with these smudge sigs. No offense but it's not helping you at all. They look "okay" for your level of knowledge but they aren't going to get you anywhere. Right now all I see from you is a smudged background and a render over it in like all of your sigs..
As for which one looks best I would say the last one just because it is the original. You need to learn to use the eraser tool on some of your adjustment layers. Like easing the area around the mouth and ears on all of the other ones would make this look a lot better i think