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: BCR

WAV appeals to the audiophile mind, probably because it is as close as you can get to the CD-format (uncompressed 16 bits / 44.1 kHz PCM audio).
In your audiophile fervor, you rip all your CD's 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 can use the following strategies:

Don't tag, use a well defined file structure to browse your collection.

You need meaningful file names.
Use a fixed name convention like track/composer/album/opus/song/year/performer.
Some player software can populate their library by parsing the file name and the reverse, renaming the file using the information in the library.
Maybe they can stomach something like this:
1_Franz Schubert _Schubert: Lieder, Vol. 2 (Box Set)_D. 699_Der entsühnte Orest ("Zu meinen Füssen brichst du dich"), song for voice & piano _1820_Dietrich Fischer-Dieskau / Gerald Moore
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
Don't tag but use a cue sheet
Don't use WAV but use a lossless format which supports 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.