Canton Village Quilt Works
http://www.cvquiltworks.com/shop/ is a fantastic source for lots of fabrics, I especially love the Kaffe Fassett selections here. Excellent customer service, broad selections, good prices & great sales----not to mention lots of giveaways & fab blog, too.
Ericas.com is my absolute favorite spot for 30s reproductions & some applique items & they offer international shipping deals when they have shipping specials (not just limited to US like SO many others).
Fabricworm.com & Sew Fresh Fabrics etsy shop
http://www.etsy.com/shop/sewfreshfabrics are great sources for modern fabrics! I have my eyes on several must-have bundles as we speak.
Have a lot of other great places I've ordered from but these are my top ones so far.