My quilts to this point have been "utility" quilts - quilts to be used and washed and used some more. I have used a variety of fabrics, including wal-mart fabrics, recycled clothing, rayons, poly-blends, and quilt shop cottons.
I have had ONE fabric give up the ghost on me in a quilt, after only 3 or 4 washes, it just got thin, frayed, and came apart. I used it in two quilts, and had to patch both. The fabric didn't seem thinner than usual, it was brand new, 100% cotton, but the quality was off somehow (it was a very dark blue and I wonder if the dye had something to do with it), and it didn't hold up. I believe it originally came from wal-mart but wouldn't swear to it, as it was a large chunk given to me in a bag of scraps.
I used a poly blend that appeared a little thin, but it is holding up fine (in the same quilt).