Change it up Precor AMT (Adaptive Motion Trainer): Unlike other ellipticals on the market, it features a free-form, user-determined foot motion that can, on the fly, change from a vertical stepping motion to an all-out, full-stride running motion. Likes: Exhilarating, effective and addictive. I loved the variety and challenge; it can be a different workout every day -- or every minute. Allowing you to move the way you want, from easy to all out, it encourages a harder workout than a normal elliptical. The stride length automatically varies from zero to 27 inches, as you step, stride, run, walk or anything in between. Includes resistance adjustment, heart-rate programs and a variety of workout programs but no elevation controls, only a lighted "interactive stride length" dial that lets you watch and experiment with your own real-time motion. Relatively floor-space-friendly at 56 inches long. Dislikes: As a commercial-grade machine, it's priced like a used SUV. Price: $7,995. (425) 486-9292; precor.com.