Walk Away the Pounds (WATP) uses very simple movements: walking in place, knee lifts, etc. WATP videos take no coordination whatsover.
If you want something that combines aerobics with a good upper body workout, the earliest Firm videos are great. (I haven't tried the newer ones.) It takes just a bit more coordination than WATP, but not so much more that you won't be able to follow along the fist time.