Hmm.
First of all, smile. Very few girls want to talk to a guy that looks like he's one minute away from an anger attack.
Secondly, In terms of style, I think that only the last picture would get any favorable reviews here. It's a nice shirt, and it seems to fit you reasonably well(maybe a wee bit too large, but hard to tell from the picture).
The hair looks good, short, classic, and low maintenance.
As for the polo shirt, I'm of the opinion that no one should ever leave all buttons unbuttoned on a polo. So button at least one and then you're pretty much good to go. Also, sit straight. Slouches are unsexy.
I'm sensing that you're doing this for the girls, and if that's the case, then you need to consider what kind of girls you want to get. If you want to get classy ladies, then dress in a classy way(aka no sleeveless shirts or gym attire, at least not when trying to impress her).
The pants in the first pic look pretty good. They seem to fit pretty well, so keep those.
As for the rating
Pic 1 If you're going for the badboy look then I'd say a 7/10
Pic 2 Classic relaxed, 6/10
Pic 3 Not rateable, just not enough info.
Pic 4 6/10
