Second image, first off, looks cool as-is, and if anything's played with will take away its niceness. Well, maybe getting rid of that red dot might be an idea... Third and fourth don't really need any touch-ups for brightness, IMHO.
I tried on the first one, and this is all I could come up with. (Hope this looks good. My LCD monitor is shit, and I shold switch back to my CRT one of these days for image quality.)
![](http://s143.photobucket.com/albums/r155/FlyingGremlin/th_improvphotoshoot001nh1.jpg)