Cardio Ideas

befferknees

At my gym, I currently go to Planet Fitness (Love it), there are a couple machines that I really enjoy using, the Arc Trainer and The Elliptical. I recently noticed last week when I started being serious about my workouts to lose weight, that my body was stressed from pushing myself too hard.
I normally do my cardio before my weights. I do Arms and Back on Tuesdays, Abs on Wednesdays, Legs on Thursdays and pure cardio on Friday, Saturday, and Sunday.
I am just curious as to which programs would be the most useful on these machines.
I use the personal trainer on the elliptical and train with aerobics. I am going to try starting off from the lowest levels and working my way up and see how that works.
Does anyone else use these machines and has had a positive outcome from their regime? I've seen that the Arc Trainer seems to burn the most amount of calories in the shortest amount of time, but to be completely honest, the programs on there are quite a mystery to me. I've just been switching around them to find my perfect fit, but if there is a great program that anyone has used on there, I am willing to try it out. Anywho, my thoughts are kind of jammed together.
Or, if you haven't tried these, but have had positive outcomes with other cardio work outs what are they?