Do NOT use WAV. There is no standard for how to store the metadata (title, categody, bitmaps, ...) so this is typically stored separately. Many people have experienced losing this data in connection with backup restores or move between systems.
I use iTunes with AIFF since harddisk is so cheap that I don't see a need for compression, but both ALAC and FLAC should be fine too (you can convert either to WAV or AIFF at any point since the compression is lossless).
AIFF is fine on Windows, but not all software will support it (I use iTunes for Windows on my desktop and for Mac on the Hifi).
I use iTunes with AIFF since harddisk is so cheap that I don't see a need for compression, but both ALAC and FLAC should be fine too (you can convert either to WAV or AIFF at any point since the compression is lossless).
AIFF is fine on Windows, but not all software will support it (I use iTunes for Windows on my desktop and for Mac on the Hifi).