Great advice from everybody! I'm going to contribute my 2 cents here since I'm someone who has lost 65lbs in the past 2 years and kept them off.  I started the challenge today and also I'm studying to be a personal trainer so I do a lot of reading from different sources.  Everyone is different and there is no one way of doing things, just like anything else in life.  Why don't you try some cardio/plyometrics, those exercises really burn fat and help you keep your muscle because they are explosive.  One 15-20 min. session every other day is all you need for cardio.  I also love Zumba and I just do it whenever I have time to do cardio for a long time, is like a bonus.  But seriously, a great cardio to do is plyometrics because you are using your own body weight.  Sample exercises are:  Burpees, Jumping Lunges, Jumping Squats, Jump rope, etc.  You can email me at raqueluz@gmail.com and I can send you some sample workouts that I do.  Anybody reading this can email me I would love to help, we are all here to help and support each other aren't we? :-)

Thank you for your advice/input.  The only problem I have is I have some nerve damage in my right foot, and it just kills me when I do high impact on it (ex:  ZUMBA :( , the treadmill, running, jogging, etc.).  I've tried the stationery bike (boring, but it didn't hurt @ all).  I haven't tried the elyptical yet, but I will try that AND the stair climber.