I buy Kona White a lot from Joann's. If I want something a little less bright, I believe the white I choose is the Kona made for dying. (I hope that doesn't come back to bite me in the butt in the future...)
I also keep my eyes on the remnant bin for white on white and other lights and neutrals. I love to mix them up in scrappy quilts so they have a more homey feel.