I go off and on Jillian (we're taking an off period right now LOL) but I like a lot of her workouts.
Her two yoga workouts: Yoga Meltdown/Yoga Inferno spice up yoga with fast transitions and bodyweight toning. These are fun and good for people who don't like yoga...they're definitely not "real yoga." YI is a little harder than YM.
Killer series: Her Killer Arms and Back has great upper body work with cardio, Killer Abs has more ah, creative moves and is more total body than abs, Killer Buns and Thighs has great leg/cardio workouts, and I don't have Killer Cardio or Killer Body. My favorite of these is Killer Arms and Back then Buns and Thighs.
I like Ripped in 30 more than 30 Day Shred, but they're a lot of the same, total body with cardio in the 3-2-1 circuit if I recall. They are a great use of just 30 minutes.
I am just okay on the two 10 Minute Body transformations, to be honest, but I haven't done every chapter in each DVD yet either.
I like Extreme Shed & Shred for a longer Jillian fashion circuit workout with total body bodyweight toning plus cardio. I have Hard Body but haven't actually tried it yet, LOL! It looks like good toning with cardio though. FYI I don't attempt to go very heavy at all with Jillian workouts.
I really like 6 Week 6 Pack for a great HIIT style workout with an ab emphasis (I think this one is much better than Killer Abs for one looking for an "ab workout") Also this one is a little different in that she does one much longer circuit that is repeated once, instead of mini circuits like her other workouts.
Go at your own risk (horrible form etc. etc. - I can totally understand the criticism this one has gotten on VF) but to be honest I actually like her Shred it with Weights workout. But I do have prior kettlebell experience and don't blindly follow their moves.
BFBM/NMTZ are really popular on VF but I never really got into them. I think because I like her shorter 30 minute-ish timeframe and mixing toning and cardio. These are longer and all toning or all cardio, I believe.
I just picked up her kickboxing DVD but haven't done it yet. I was deterred for years since she only leads on one side, but since she repeats the circuit, you can make it even for yourself.
In the past I did a rotation of Body Revolution and thought it was a well produced and thought out system. By phase 3 those were some tough workouts! I haven't ever attempted Body Shred system yet but will admit I did pick it up when the price was dirt cheap