i go by favorite artist at that time, and then favorite cd by that artist, so the most frequently used cd's are in the front.

there is also a genre look.

i tend to buy the cd, bring it home, rip it, burn it, and leave the originals at home, and use just the burnt copies. i always destroy cd's, and this way i increae my mp3 collection and keep the originals in good shape. i dunno. it's something new i started.