I had to start buying online recently and haven't been sewing in years. I used to shop at Erica's all the time in person and was so sad when they closed. They had the best applique supplies, kids' fabrics, and 30s Reproductions!
I've used quite a few Etsy sellers but the shipping is getting pricey since I purchase from several shops at once. Missouri Star Quilt Co. has been mentioned several times but I tend to only buy templates and precuts there. I've placed several large orders at the Fat Quarter Shop and have been pleased with the results.
Connecting Threads and Ebay had a couple fabrics recently that I'd been searching for but the results were disappointing. I'm too far from most quilt shops and am rather particular about the prints I purchase...so I'm also looking for suggestions. I tend to buy modern fabric designers' lines {Heather Ross, Aneela Hoey, Denyse Schmidt, Kaffe Fassett, Essex Linens}, Kona cottons, and 30s reproductions. I found Twiddletails for 30s and plan to purchase there soon.