I'd argue that FLAC is the better choice over WAV. Especially since storage space is a concern for you. In short, you get the same audio quality as a ripped wav file (the data is identical once it's converted by your player), It may not compress as deep as an MP3 but there is no data loss and the amount it does compress adds up to a huge difference over WAV in bigger song libraries.
FLAC can be converted to any other current format and in a worst case scenario, you can convert it back to a WAV file. Lets face it, a new audio format that is so much better that it gains universal domination is likely to either a.) quickly have flac to "newtech" converters developed by hobbyists or b.) it will come with a tool that requires or is quicker to reconvert all your CDs again making WAV just barely better or not at all.
On the basis of tags. I used to think like you. A well thought out naming structure is all I needed. However, if you are like me and enjoy an oddly large spectrum of music styles, then you will find yourself wanting to someday filter by genre.
Case in point, I love almost all music from heavy metal to classical and I almost always have my player on random so I get an mixture of rock, blues, jazz, indie, whatever really. However, despite an enjoyment of classical, it is just so radically different from the above that it just didn't seem to fit in together and vice versa. I normally have "classical, and more the more classical or varied styles (flamenco, world, etc.) " filtered out when I listen to 'rock and more modern styles' and I have "rock and modern styles' filtered out when I listen to the classical set.
This is done easiest if you have tags. Also, sometimes you do get in a mood. You feel like playing a bunch of random punk or a bunch of jazz, maybe even a certain kind of jazz. Also easier done, if you have tags. Album info is also surprisingly interesting when people ask "what is that from?"
Just my thoughts, certainly not a rule.
