I'm looking for an MP3 player that DOES NOT require iTunes or Windows Media Player to update - I want something that operates as a mass storage device, and you simply drag/drop MP3 files to it. Anyone know of something that fits the bill?? I know not to look at iPods, or the Zune, but I was surprised how many MP3 players require WMP 10 or 11.

An optional AC adapter would also be helpful, but the main requirement is mass storage device support for updating music.