The my overall favorite online/brick and mortar quilt shop is Web Fabrics. I first ran across the name at the Mid-Atlantic Quilt Festival in Hampton, Virginia. They had a very nice selection and display of fabrics set up at the show. The ladies at the show were really nice and helpful to everyone.
The brick and mortar part of the store is located in Purcellville, Virginia. From the outside it looks small, but looks in this case are deceiving. Once you enter the store, you walk into heaven. Huge amounts of fabrics everywhere including a very nice section devoted to Batik and Bali Fabrics. The shop carries all the major fabric companies, so if you are looking for Contemporary, Traditional, Reproductions or even Novelty Fabrics, they have it. They also have a large selection of Fat Quarters, Notions and books. The staff is very helpful and willing to help you pick out what you are looking for.
The online store, is what makes it one of the top online quilt stores. You can search varies ways to find the fabric you are looking for, if it is by Company, Color or even theme. Once you locate the fabrics you want you can compare them on the design wall they have on the site. This is very helpful in looking for that right combination. The shop also offers a yearly block of the month, where you tell them 3-4 different colors and they will send you the fabric with a fabric key, and monthly block through email. They are lots of fun.
Webfabrics.net is usually the first stop on my online quilting shop for when I need to look for inspiration or particular in fabrics.
When you get a chance take a look at this fantastic quilt shop, or if you are in Northern Virginia sometime, take time to visit the shop.