here are some:
in predators 2010, skinny Adrian brody beats the living shit of a super predator with a tiny hammer. but in the original movie Arnold Schwarzenegger hits a normal predator a giant tree branch and punches it but he just shrugs it off.
in Friday the 13th part 7, Jason looks like he has more of a normal person's head rather than a deformed one.
in crank 2, Statham goes through the whole movie getting electrocuted without a single scratch, except the end of the movie where he finally catches on fire because the plot demanded it.