http://www.thousandsofbolts.com/
http://www.hancocks-paducah.com/ Their web sales. Best deals around
GREAT source for inexpensive LQS quality cottons:
http://www.quiltingcotton.com/
I've had good luck here but I don't like the way their site is set up.
http://www.whittlesfabrics.com/cgi-bin/Store/store.cgi
http://www.fabricdepot.com/
http://www.connectingthreads.com/Quilting.cfm Great customer service! They have always stood behind their fabric with me. One time they sent the wrong color. Called them. they sent me the right color and told me to go ahead and keep the wrong one (a full yard)! YAY free fabric. another time they forgot to include a package of needles, sent me a new package no questions asked. I also love them for their batting sale which is going on right now. $50 order gets you free shipping. Buy a few yards of fabric and a couple of packages of batting and you are there!
Have fun shopping.