If there's one piece of fitness gear that's misunderstood and underappreciated, it's the Smith machine. The large racks, which feature a barbell fixed on rails, are often derided as being for weak newbies who can't or won't learn to lift with good form using free weights.

But the Smith machine can be used for so much more than just a squat rack with a built-in spotter. (More on that later.) If you know what you're doing, investing in one of these rigs can do wonders from your home gym space, giving you a wide range of options for your weight training.