My favorite is "Needle in a Haystack" in Severy, Ks. It is located outside Wichita and we stop there everytime we are in the area.
It isn't a great big store, but she has it laid out so you can find things so easily. Her prices are about as reasonable as anywhere, and you get good service.
Missouri Star Quilt So. is hard to beat for online. I love their tutorials, deal of the days, and just general something always to see on their site.
Mariah