Jillian Michaels just released a new cardio DVD that sounded like one I could handle, Jillian Michaels: Kickbox FastFix. I downloaded it for $9.99 on itunes and tried out workout 1 today.
This is the first of her workouts that actually is 20 minutes from start to finish. There's not a warmup and a very quick cooldown (that lasts maybe 2 minutes total--I cooled down for longer because I don't want to be unnecessarily super-sore) so you have a solid 17 minute cardio workout. I watched the tutorial on proper form before doing the workout, but still had difficulty maintaining proper form at the pace she led the workout. This is not Jillian's fault; I am just a bit uncoordinated :). Workout 1 focuses on the upper body and does incorporate weights on 3 or 4 different moves. I worked up a good sweat and had no joint issues while doing all the moves--yea!
All in all I liked the workout, I just have to work on my form. Down the road, I could see myself doing multiple of these workouts back to back seeing as how they are short.