I have a wall full of Rubbermaid bins and a small closet full of fabrics. All of which I go through fairly frequently. When I do, I usually pull out some that I donate to my guild's community service bee. After that I feel so good that I go out and buy some more. Mostly I shop either on-line, or from my LQS. Sometimes I buy stuff at at our yearly trash 'n treasures sale which helps with fees for the speakers and teachers we invite to our guild meetings for workshops and trunk shows.
Right now I'm trying to use up some of my two bins of "strings" and scraps by making string and scrap quilts exclusively. That will keep me going for a while.
I have to admit, sometimes I buy fabric just because I love it. 8)