With that said - the best most effective workout are the one you will do- eat less move more but if you want to have nice looking definition Weight lift- heavy weights full body workouts - none of that "tiny weight multiple rep" crap either-
I agree with dbacker - the program you will do sounds simple but it really is the best advice. I'm new to this site but not new to this journey. Not knowing much about you, I'll share some things that Dr's and others have shared along the way that have helped.
Get a pedometer. Some are better than others. I like what I'm using right now but I've heard that the Digi-walker brand is the best. Since I started walking a minimum 5 miles a day - doesn't matter how I do it and lift 30 minutes 3 - 4 days a week, I've seen some great results but it's only been a little more than 2 weeks. I make sure at least 30 minutes of a walk is aerobic. My doctor told me I have to do this to maintain if I don't altar my eating (I have though) and 7 miles a day to lose. I'm 50 yo so if you're younger it will be easier. I find that getting the walking in during the day by planning the night before works for me, most days. It wasn't that I wasn't any other workouts, I just wasn't doing them "smart enough."
What are you going to be able to keep/fit in your life? Try new things out w/o spending a lot of money at first. Think long term about what you will do and enjoy. Incorporating some weights is a must for all women!!
PrimosHat- I just ordered TapouT XT, it looks awesome! How far are you into it? P90X was a bit annoying and I've also done Turbo Jam/Turbo Fire/ChaLEAN Extreme/Brazil Butt Lift, all have great attributes. Lost my first 50 lbs. with a combo of the above, plus Zumba. :) I'm excited to get into Tapout XT!!! I've always loved MMA/Boxing routines and as much as I love Chalene's DVDs, the kick/punch sets seem a bit sloppy sometimes and I look forward to some true MMA routines. Is it as good as the ads show it?