Stretch Break's best feature is its animated figures that demonstrate the stretches. The 3-D figures are slightly strange-looking (some are even creepy), but that's easy to overlook. They also represent people of various ethnicities and ages. This version adds music, too, all of which is New Age-y, but relaxing. Thankfully, you can turn it off if you don't want to hear it.
The program is extremely flexible (no pun intended) -- you can set which stretches you do and the order in which you do them. It also includes text-based Ergo Hints (reminders about proper ergonomics).
On the downside, Stretch Break doesn't lock you out of your screen, a feature some computer addicts may need. And there's only one type of stretch (for X minutes/stretches every Y minutes of computer use), as opposed to a couple different levels. For example, some people benefit from shorter stretch breaks every 5 minutes followed by longer stretch breaks every 50 minutes.