I have tried all of the versions of this game for the PS2. We have Gamefly which is like Netflix, but for video games. I tried to do this for cardio, but it's not working too well for me. I mean I am burning alot of calories, but I don't think it's making a difference to my body. I am going back to walking/jogging for my cardio and doing DDR for fun. At least this way I can be twice as active.
As for a favorite song... I don't really have one. There is usually one or two songs I really like on each version of the game.
Doing something, even not perfectly, is better than doing nothing.