1) .wav 2) .flac 3) Apple Lossless 4) .aiff 5).wma 6) .mp3 For me, I tend to listen to .wav and .mp3 mainly because; .wav is like ripping the music file straight from a CD without any compression of the sound quality and detail for bass + mid. & high tone. and .mp3 is very easy to find on internet but the down side is poor quality of sound stage and bad compression of sound tone. all of the above is just my opinion and may not be actual facts...
For Music,i don't really have any preferences but i mostly listen to .mp3 because it's easily available. never heard about the .flav and the .aiff format...
Mp3 is pretty common. I've seen flac for concert stuff and WMA as well. The other ones are new to me lol.
Not opinion but fact, mp3 is shit due to it's lossy compression (much infomation is lost) however is reasonable unless you are a audiophile and own high tech speakers. I myself rather flac if available cuz besides being lossless, it has better compression and other features.
mp3 because not everything is available in flac/my harddrives not big enough/ my internet is slow/ i don't have >$300 speakers/ i am not kontradictions lol
mostly mp3, but there are some apple lossless, thanks to iTunes, just cbb to use other program to convert CD songs to mp3