this is pretty tight competition, but i would probably have to go with Snake, cause if u look at the back of the master chief, where his neck, is it isnt an armour plate but some kind of neck strap rubber plate or sumthing. Which looks pretty easy for Snake to slice through...Or dress up as a crocodile and eat him
Hmm...tough to call...master cheif isnt much on the stealth so Snake could just hide out and pelt him with sniper bullets. On the other hand Cheif has radar...but its only for motion if snake stays still (or for you halo players crouch) cheif wont find em... I like Snake better tho, so im going to say him