Man, this could turn into a long debate! But here's my opinion. For certain exercises, certain machines are good, and free weights are good for others. Both can be used to a full advantage, if performed correctly. Cables are good, Hammer Strength where each arm, or side, is Isolated, and of course free weights are good. I personally prefer free weights, with cables for certain deals, like Flyes, curls, triceps, etc. I rarely ever use true machines, but do like Hammer Strenths.