Apple Lossless, AIFF or WAV for itunes?

I have ripped my collection in itunes to AIFF but as I consider buying a NAS I here most are not compatible with AIFF this true? Of the three which is best for sound quality and maintaining the correct metadata?
Thanks for your help!
FLAC or ALAC. Both lossless. One is controlled by the Evil Empire, your choice...

As long as you have up-to-date codecs and your processor isn't so low-powered as to struggle with decoding flac or alac, then all 3 will sound identical as all are lossless. Also the 'as long as" scenarios described in this post are not common. Just go with flac or alac, whichever your system supports, or flip a coin for either if both work without any tweaking.
I have noticed in my system that wav sounds better... even using dbpoweramp to convert flac to wav, the converted files sound better... Can't coment on AIFF as I use PC, but thought it was worth mentioning.