I signed up with BMG many years ago, then I found out about yourmusic a couple years ago and bought many cds through them, until the price increase...now I buy more from BMG, actually only when they have the buy one and get 4 free, which turns out to be cheaper than their sister site, yourmusic. Selection is mainly mainstream.
Amazon used/independant dealers fulfill my wierd, offthebeatenpath, musical explorations.