I agree with bearisgray; if the fabric isn't color fast (& the thread, too), I don't buy it.
I will say that sometimes there are surprises in the upscale quilting fabrics that Joann sells. A client of mine found a Robert Kaufman fabric in that section of Joann -- with a 50% off coupon, it turned out to be quite the steal! That said, I've also bought fabric (back when I didn't know any better) fat quarters from Joann that turned out to be basically sheer (if you held it in front of your face, you could still see objects on the other side of the room -- they just took on the pinkish hue of the fabric). I ended up using them to make fabric yo-yo's. Really they were useless for anything else & I'm not even sure the yo-yo's will hold up in the wash.
I also look for frayed edges on the cut edge of the bolt. If the fabric is already fraying before it's even made it out of the store, it's not going to hold up well in a quilt. Someone mentioned novelty fabrics, so far, the best brand I've found is V.I.P Fabrics, available at my LQS.