Do I need to re-rip?

dBpoweramp is $38, but there is a free 21-day trial. It supports AIFF and ALAC as well as WAV, FLAC, and mp3. It does automatically download album art and tags, but I find that a certain amount of tag editing is still often necessary. All in all, dBpoweramp is a great program. EAC is a freebie that gets good reviews. I've not used it, but I don't think it supports AIFF or ALAC.

If I understand correctly, AIFF is basically just WAV with metadata added. The audio data is the same.

If you are using iTunes and like to have all of the composer, artist, dates, etc., then you probably don't want to use WAV.

AIFF has the L and R data fields reversed. It also has different offset and control info fields. This makes it sound worse than .wav somehow. Like listening through a tunnel. I think even ALAC might be better....

Steve N.
Empirical Audio

So...isn't ALAC apple lossless? If so, then I don't need to go thru the bother of re-ripping - right!

Some people report hearing a difference depending on format and even on ripping software. They report that a WAV file ripped with dBpoweramp sounds different than a WAV file converted from Apple Lossless (for example), even if the files are the same. My suggestion is to do a few new rips yourself directly to WAV and compare that to your Apple Lossless file converted to WAV. If you hear a difference, then you may want to re-rip a portion or all of your library. If you hear no difference, then just converting your existing files is probably OK.