The Marcy Diamond is the first of many “Smith Machines” on our list. A “smith“ keeps all movements vertical, which is beneficial in many ways, but the optimal safety it provides is especially helpful in a home unit. The Marcy Diamond tops our list of Smiths because of its complete slate of possible exercises including lat Bar and leg apparatus. Many Smith machines either fall short in these two categories, or don't include them at all. The Marcy Diamond is about as close as you can get to bringing home all the free weight capability you have at the gym.