I'm glad to see equilter mentioned. They have such a huge selection I'm always amazed. Seems like it was around Christmas they had a free shipping deal and I loaded up. Otherwise, I always look for free shipping such as fabric.com has. Fabric can be heavy and bulky and I'm not usually willing to pay an extra .50c to $1 per yard.
I avoid places that show prices by the 1/2 yard. I suppose they're ashamed of their per yard prices and are trying to mislead customers. It offends me that they must think I'm that stupid.
A place I don't believe I've ever seen mentioned but have ordered from several times is
http://www.corinthianmills.com/.