Since I workout at home, mostly with videos, I am constantly on the lookout for new videos to keep me going. I'm a bit OCD about my workouts; I will do them religiously, fanatically...as long as I'm interested in the videos and feel like I'm seeing results.
With the help of Netflix, I've tried a lot of videos. Some are annoyingly simple, some are fun, and others are hopelessly dated. But I've found some good stuff and, over the years, have definitely become more fit. And, in so doing, have found it more and more difficult to find challenging workouts.
Some random thoughts on what I've seen... Jillian Michaels is annoying but difficult. I hate instructors who don't actually do their own workouts beyond the first demonstration. However, I may give Jillian a third chance later on in the future. I like Kimberley Spreen, though she hasn't produced much recently. The same goes for Violet Zaki. I use both of their older videos. Ellen Barret does fun yoga/pilates...when I'm looking for something lighter and less challenging.
My new favorites, and those who work me out almost every day now, are Jari Love and Michelle Dozois. I like Michelle's older work but her new Peak 10 series is incredible. I've never been worked so hard with her cardio strength and interval cardio workouts. Holy cow! I highly recommend them if you're advanced and need some new, fun stuff. You'll sweat like crazy!
Jari Love has been around since 2005 or so and I discovered her videos over a year ago. Recently though, in an effort to focus on my legs, I started doing more and more of her videos. Some in her Get Ripped! series are mainly weights with arm and leg work. You'll do bicep curls for five minutes, squats for five, deadlifts for five, then lunges for five, etc., etc. This will definitely make you burn. Some of her other workouts have cardio interspersed with the same crazy leg and arm work. They're a real challenge.
Alternating each day between Michelle and Jari, I'm really seeing results in my legs - for the first time in my life! It's a very slow process....but very exciting!
I hope this gives you some ideas if you're looking for a new workout!