I only did the Batman, Predator, Terminator, Aliens, & Robocop list because you mentioned Robocop and all five of them have fought before. Aliens are ok, but Batman has taken out the king of the aliens multiple times: Superman. Predator's shoulder cannon is about equal to heat vision. Nothing else they have is all that advanced, they're just hunters...I'd put them on the level of someone like Lobo or something. Although I guess they have that invisibility thing...but I think they'd go hand-to-hand with Batman, where he'd win. Terminator would just be another low-rent robot. Everyone's taken out the likes of them in comics and Batman's no exception.
But, yeah, I don't know if Batman could deal with Mega or especially not Samus. And no, Master Chief couldn't even hope to take her down. She's too fast for him to run away to recharge his shield.