I can't stand the sound of MP3s (although I find that the MP3 enhance setting makes them sound better).
I listen to FLAC, but I'm running out of room. I'd love to use OGG, but tags don't work and I don't want to switch to folder sort method. I hear no echoes on OGG, though (firmware 1.17).
In the end I chose FLAC and I am constantly swapping out music since I don't have enough space. If you don't mind folder sort mode, OGG sounds great. But the player is most compatible with MP3. If the sound quality doesn't bother you, it's the best choice.
Last edited by piller; 03-04-2009 at 06:57 PM.