Probably every person who sews already knows about Fabric.com but I wanted to mention it anyway because, if I am remembering correctly, it is the first online fabric store from which I ever bought fabric. There was a time when I thought I would never buy fabric online. You have to actually see it and touch it. But my local choices are extremely limited. There's the fabric department at Walmart and there's a small quilt shop, which only opened a couple of years ago. The next nearest fabric stores are about an hour's drive away. And online there is so much fabric. How could I not?
Fabric.com has a huge selection of fabric and very good prices. Their website is not one of my favorites but it's okay and shipping time is about average.