I just saw this thread (I travel a lot this time of year). Like most of you, I sort three sections: Classical (by composer), other (alphabetically by artist), and Jazz--that massive 90%--sorted alphabetically by artist with each artist's stuff chronological. But, like others, I do goofy shit, especially with compilations and various artists. There I sometimes choose the artist I like most and put it under that name, and occasionally by title, if it would make it easier to find.
And, defying all these rules, I shelve my "Jazz in Paris" collection separately and organized by NUMBER, because...well...I just like the way it looks that way! The irritating thing is when I forget a given set (like a Mosaic set) has an album by a given artist, I see that separate album in a store and buy it, then come home to discover I already have it in a set. But then, I buy other dups now and then because my aging memory sucks. So it goes!
gregmo