Hammer-Strength has some good machines, but "honestly" these machines gives you a feel of "more strength than you truly have". (example: 1 arm rowing with 330 lbs for 12 + reps, dumbells around 200 lbs,
a big difference...)
On most of them you can load much higher amount of weight than you can use with free weights.
But, i like the motion..going from a nearly perfect stretch to a nearly perfect contraction.
My favorites where the incline bench press, the iso-row (low-row), and lat-pulldown. You can do all movements with two arms or unilateral (with one arm).
The optimal workout always include some kind of free weight training + good machines.