In my experience Sony has made the best. They support multiple file formats including the lesser used ones. Their product also comes with its own unique software that allows you to compress your Mp3's to fit as much music as possible onto a single CD. They have a very resistant anti-shock system that lets you enjoy the music without skips.
If you are looking for a mp3 player or a Cd player, the best brands would be: Iriver, Sony, Samsung, Philips, the Ipads are verry good, if you are looking for something cheep try Eboda