http://www.quiltshops.com has a search engine for its member shops. It's great for finding something that is not on your favorite websites. I've ordered from many different shops there and never had a problem.
http://www.thousandsofbolts.com has fabulous prices and my favorite part is that the fabrics are organized by colors. You can also narrow the search by manufacturer/line. They have a new color matcher feature which I have been using lately to cut down on the hundreds of choices.