Metriod

[Lee]

the colors are temp. i wanna improve this, how can i?
http://www.imgmag.org/images/lee1/SAMUSxFUSED.jpg

[gekitsu]

first, you could add some more fierceness. wasn't one of samus' features that the head in the helmet looked way too small and was kinda buried between her shoulderpads?
also, a bit more power in the lines could help. exaggerate, make guns large and give them details, let the battlesuit accentuate muscles... she doesn't need to look like a woman, it's samus ;)

second, i'd suggest to add a surrounding, even if it is just colors.
placing this figure in dramatic light in front of a darkish background will give her a) a more menacing look and b) with shadows and reflective lights and such, you can tie her to the ground, give her a firm stand... (never underestimate what a simple drop shadow can do!)
color wise, i'd go away from the color selections you chose... everythyng looks plasticy... would you run away from someone in a plastic battlesuit?
take the helmet: paint it with a quite high saturated red (a bit on the carmine red side of things), give the shadows a high saturated red, too, just a lot darked (more than halfway down to black). do the same with the highlights and give a little white specular light to the most important points.
make all the renderings very harsh and don't give the first red too much space - lots of shadows and lights, so you make it very shiny and metallic. also, you can add patches of dark green in the shadows or whatever color you gave your background to tie it together.

hope i helped a bit.