First of all, to qualify for this list, a fighter must be a bona fide heavy hitter. If he can't force a fist or a leg through a brick wall, then he should go puff his chest somewhere else.
Also, if a guy isn't an active top 10 fighter in his division—hence the mention of power rankings in the title—he needs to exit stage right.
So while guys like Jeremy Stephens, Shane Carwin, Chris Leben, Jimi Manuwa, Mark Hunt and Melvin Guillard possess serious knockout power, they don't make the cut.
This list is in no particular order, but it most definitely packs a punch. Enjoy.