among the many mp3 players i've owned (ipod, creative zen, sandisk e280, samsung t-9, rio), i can't honestly discern substantial differences in sound quality, at least with compressed mp3 files--all of them served their purpose. of the above, my sense is that the samsung and ipod players had the highest gain and sounded a little better, although the distincitions probably aren't cost-effective. what was much more significant was the headphones--after i pitched the standard earbuds and bought really good, lightweight over-the-ear phones, my enjoyment really peaked. koss portapro and sennheiser px-100 (both easily found for around $40) are absolutely incredible for the price and, to my ears, sound much better even than the pricy shure, etymotic, etc. in-ear stuff.
