I'll difinitley have to say TERMINATOR because a TERMINATOR could probably kill anything with living organs,also mentioned someone said a T-1000 would win but not a T-101/1-800 well the T-800 defeated the T-1000 lets not forget so if the T-800 was able to come on top somehow with the right weapon to destroy the T-1000 and cause it to fall in maltein steel and die,I dont see why the TERMINATOR couldnt kill predator easy,seeing in T1 The T-800 punched through a mans stomach at the beginning of the movie and ripped his heart out. predator wouldn't last,it be a good fight but i'd have to give this one to TERMINATOR/T-101/T-800 its defeated all other TERMINATOR's like in T4 it ripped a T-600 in half and the T-600 was a foot taller than the 800 and the T-800 ripped it apart like a toy and killed a half human/half TERMINATOR which is marcus,yup TERMINATOR wins hands down i rest my case.