I'm looking into getting a pair of decent quality headphones, and I've seen a couple of models from different brands. I'd like to get a comfortable pair with cups that fit right over the ear, but I'd also like to be able to use them on a portable cd player so I don't know if there's a power issue there. The main thing that I'm concerned about that I've heard is sound leakage both from noise outside going in and from inside the phones to the outside. I don't know how big of a problem this would be as I usually have music in a public place. And the only company I know that offers noise-cancellation is Bose, which are really pricey. I don't really want to spend over $150. (120 american) Anyone have any recommendations?