Experience, credentials, education and success.
The Colleen Bawn - 1924 is rated/received certificates of: UK:U
Colleen - 1936 is rated/received certificates of: USA:Approved (PCA #1782) USA:TV-G (TV rating)
Trainer and Temptress - 1925 is rated/received certificates of: UK:U
The Trainer - 2013 TV is rated/received certificates of: USA:TV-14
CP Trainer - 2007 V is rated/received certificates of: Netherlands:AL
Ellen - 1994 The Trainer 2-9 is rated/received certificates of: USA:TV-PG
Nicki Waterman Your Personal Trainer - 1999 V is rated/received certificates of: UK:E
The 1790 Biathlon Trainer is rated at 450 FPS
The Mindy Project - 2012 Danny Castellano Is My Personal Trainer 2-12 is rated/received certificates of: USA:TV-14
The Sole E55 Eliptical Trainer is a great workout tool for your home. This is a perfect machine for your daily workout and it can accomdate up to 375lb of weight.
The highest rated home gym machine would be a Cross Trainer, otherwise known as an Elliptical. These are much safer than a treadmill, and are easier on your knees, by reducing impact.
The best elliptical trainer on the market that is the best bang for the buck is the Precore EFX 5.25. The elliptical has a lifetime warranty on the machine's frame. It was rated 9.8/10 for the elliptical's accessories. It was also rated 9.5/10 for the help & support.