I havent done cardio in a while... but elliptical or rowing works the best for me. I have a heavy bag and speed bag in my garage i just havent hit it since before my accident used to jump rope with 5 pound habdles too...

Hey...
As far as i know swimming is all time best and most effective... There are lot resistance present in water which means more energy require to overcome so it means more calories burn...

Swimming and running theses two are my favourite exercises and these exercises really work for me. I have lost my 15 lbs only through these exercises. But you should be consistent to get good results from them.