I'm going to play the devil's advocate and back the person that everyone seems to be ignoring; the elder predator. Aren't they hundreds of years old, and almost all of those years are combat experience. This guy is probably gonna be the best straight-up fighter here, and his tactics would probably be flawless.
Not only does he have the edge in experience, but he's gotta some pretty sick weaponry and armor. He's got those disks, and the plasma cannon (which is comprable to the plasma weaponry in Halo that takes down the Cheif's sheilds fairly quickly) could do some serious damage to either of the other competitors. And if it gets close the pred's got claws and the combi-stick, which wikipedia refers to a one of the sharpest tools ever discovered. I believe he is a force to be reckoned with and shouldn't be ignored in this fight.
I'm not saying who I think would win, b/c I think this is an awesome fight (props to the maker), but its pretty evenly matched in all 3 competitors. Just my two-cents...