WAV

WAV or WAVE (Waveform Audio File Format): Audio file format for Windows developed by Microsoft and IBM. WAV support was built into Windows 95 and has become an industry standard since. A variety of applications now support WAV files, as do additional operating system platforms, such as Macintosh. WAV indicates “sound file”, not a specific format of the file. WAV files can be 1-24 channels, 8-32 bit, fixed-point or floating point, compressed or uncompressed, etc. The WAV specification includes an “others” area, called the INFO CHUNK, which can be stored any additional data (e.g. a database, text, video, pictures, etc.). The INFO CHUNK, in the file “header”, is most commonly used to store metadata. While widely adopted, there is no standard format for this information.
Source: http://www.bcr.org/cdp/best/digital-audio-bp.pdf

This is as close as you can get to the original source. This is probably why WAV appeals to many an audiophile, it is ‘pure’.
In your audiophile fervour, you rip all your CDs to WAV.

One day you tried another player, you move the files to a new computer and observes that album title, song title, art work, all the meta data you provided are gone.
All those hours you spend meticulously adding the right information are wasted.

This is the paradox of WAV, the support for the music part is almost universal, the support of tagging almost nonexistent.

Some interesting experiments about the compatibility of WAV-tags between different applications can be found in this post: http://www.audioasylum.com/cgi/vt.mpl?f=pcaudio&m=39225

Due to all these technical problems a lot of people believe that it is impossible to tag WAV. This is not true, it's a matter of writing the tags in the info chunk.

Due to a lack of standards, portability is very low.

If you decide to go for WAV you 2 possible strategies:

Don’t tag, use a well defined file structure to browse your collection.
Do tag but make sure you can move the library and the files to another computer without loosing the correspondence between library and files because one day you will move. Check a post like this: http://www.microsoft.com/communities/newsgroups/en-us/default.aspx?dg=microsoft.public.windowsmedia&mid=eb2a555e-11ce-47d3-8921-0f996f6f1e8d

A third strategy is of course to use a lossless format which support tagging.
If in doubt if this would compromise sound quality, do a ABX comparison between WAV and its lossless alternative.

Don’t forget, lossless is lossless, given the right software you don’t tie your hands, you can always convert to another lossless format without compromising sound quality.