Most are most like Bo Flex are not trusted. Try some old fashioned running up and down stairs for your legs and try lifting yourself on a tree branch for your arms and abs.
There are many different machines that are great for exercise in the home. They are usually quite large so you will require space for these items. There are rowing machines, home gyms, elliptical...
Ellipticals are not as good as actual running or swimming but i know in some cases you have to use them if you have bad joints or are in rehab. If you have to use an elliptical make sure and push...
Gazelle exercise machines are good for aerobic workouts and to tone your legs and glutes. It is not as intensive as an elliptical, though, and as such will require more time to reach the same results...
There are various exercise machines that are good for abdominal exercises. Yoga balls are good for your stomach, you should first know how to use a yoga ball properly though for abdominal exercises....