It looks dull right now. you should get some of the yellow from the trim of his suit and make some effects on the bg.
Did some smudging and set it at a different layer mode. For eye popping colors use Dodge modes or Burn modes. Then added some gradient maps which add color and deeper lighting and shadowing.

Uploading psd if you want to see it more in depth.
http://www.mediafire.com/?gmgqfjmndjzFor your third sig I'd say it's pretty damn good.