who can play ddr really well like on the green or purple seting?
I'm guessing you mean on standard mode (green) and heavy mode (purple)?
I tend to be more on light mode (orange), but I'm getting more into songs on standard mode now. The best songs to train on when looking at moving up levels are 'Butterfly', and 'Cowgirl'. They're usually set somewhere in between each level, so it's like taking a half-step up.
A few of my friends are really good at DDR- my old housemate could do almost any song on the highest level- I was so envious, his legs and feet move like crazy!
I have DDR Extreme; and I play mostly on Standard. I used to be able to play on Heavy, but now I can't, its been to long. I started playing again yesterday, so I'm working my way up. (: