Audio format of choice for streaming.

[bleedink]

I would add to what David said above as well. Most often the type of file you are going to use to stream (assuming you want it to stay bit perfect and don't want your wav's to play as mp3's) are going to be dependent not only on the hardware you are using to stream to, but also the software that is pulling the music from your HDD, NAS, or what have you. For instance, your streaming device may or may not support say ALAC. These would either need to be transcoded by the software (not ideal) or you would need to convert them to another format if you prefer that that they play in their native state. Some software supports only certain codecs. Some hardware supports certain codecs. Some software and hardware support certain codecs in certain situations and not in others. Some examples of this would be DTS wavs, multichannel Flac, or even uncompressed flac. Basically you need to figure out the lowest common denominator between your software and hardware and encode accordingly. It seems flac seems to share the widest support. Again it boils down to both the software and hardware you use.