I agree that Jillian Michaels and Jackie Warner have some solid workouts. Jillian's No More Trouble Zones (low to no impact) and Banish Fat, Boost Metabolism are the bomb. I own her 30 Day Shred too and while it's great for a quick workout, it's not my favorite. OH her 6 Week 6 Pack is a killer abs workout!!
I own several BeachBody systems and like all of them. Turbo Fire is a blast, but may not be the best option for you considering your knees.
The one from BB I love, used the most, and got great results from is Slim Series with Debbie Siebers(not Slim in 6, but I hear that's a good one too). It really helps with my problem areas--butt and thighs!! And great arm and waist work too.
It's low-impact using light weights, but it still gets your heartrate up pretty good in certain parts, especially with lunges and squats.
eta: ooh I just thougth of on BB system I hated. Yoga Booty Ballet. Ugh. Terrible! I don't recommend that one.
Last edited by LAwoman; 01-12-2012 at 12:00 PM.