Easily Samus! She has better weapons and armor, besides she can turn into Morphoball and explode the shit out of Master Chief! ;D

Remember, folks. Samus has straight-up destroyed four planets.

Hell, that makes her better than the Death Star

This will probably happen

^ Bloody awesome! ROFL

Samus can literally cut Master Chief in half by jumping at him. MC needs a gun, Samus has a plasma cannon / super missile launcher attached to her arm. And have you seen dem shoulder pads? No way, man. No way.

hmm samus has that chozo or how they are called power suit and dna right? so maybe samus?

but she can lose in smash brothers against a plumber so maybe she isn't as strong as i thought^^

Masterchief

I would nail samus if I was master chief and make two babies. Samus Junior and Masteress (?) Chief.

and then I would nail her again

UHAUHAUHAUHAUHAUHA Oh my.. lol Nice, very nice! XD

Does Adam let her use her charge beam?

(Samus is on a different level power wise though, super speed, changing into a super charged flying ball of death, changing her blaster properties on the fly; her tech is much more comic book then Cheif's)