Very situational.
If they were stripped of all equipment and forced to fight in a cage match then the Astartes (Space Marine) would win- he's far physically superior than the rest. 8 foot tall, 2 hearts, three lungs, self clotting wounds, immune to concussions, can crush a man's skull with his bare hands, strengthen bones and can spit acid.
If they had their equipment and it was conventional ground warfare then the Mobile Infantry (Starship Troopers) would win, their equipment outclasses the others in terms of sheer destructive potential.
Of course if it was say a war in space then the Space Marines would win as the Imperium's ships are better by magnitudes than any other group's on that list. That and Space Marines are truly awesome at boarding actions.