I seldom buy fabric from the LQSs because they are never open when I can shop. I work 8-5, have a 30 minute commute, and most of the stores close by 5:30 p.m. And Saturdays are cleaning and errand days, and are completely filled. I purchase fabric at my local Hobby Lobby and JoAnn's, because they stay open later in the evenings, but I have to feel the fabric. If it is stiff, rough or thin feeling, I won't purchase it. I prefer the Hobby Lobby fabrics to those at JoAnn's, and I can get Kona Cotton for $6 a yard.
I shop on line at several of the stores that Feline Fanatic listed -- Thousands of Bolts, Fabric.com, Old Country Store. I also shop at Missouri Star Quilt Company, Cotton Club, Sew Batik, and Batiks Plus.
Also, check out Craftsy. They not only have on-line classes, they have a store where you can purchase patterns and fabric, all of it name quality. If you purchase a pattern, check the store, as they may have a kit in several different colorways.
Finally, sign up to do the next fabshophop. You will visit lots of online stores.
I see you're in Houston. I live about 35 miles north of Houston, but work downtown. What area are you in?