If you're looking for an excellent SQ device at a reasonable price, I would recommend the X5 or M5 (M3, now very hard to find). My M3 is still going 1 year strong and I love not having a main screen on the device. The portable remote with nice niché screen is very easy to use and has very superior sound quality to the iPod.
With excellent enhancement options (JetEffect, Custom EQ, BBE, Mach3Bass), its brilliant. Supports many formats (MP3, non-DRM WMA, OGG, FLAC, WAV) which is a requirement from me. The M5 has a monochrome screen (if you don't want colour) or X5 is the colour upgrade. The M5 doesn't have FM Radio compared with the X5. The X5 has USB-OTG, which is handy if you have lots of USB devices (e.g. Digital Camera) and upload pictures instantly for back-up and transfer.
Cowon have active support and firmware upgrades which is also good. If you want to be different and stand out of the crowd with an excellent MP3 player, the X5 or M5 is for you.