I like Kona. Like others have said you really have to watch JoAnn's because the mix things together and carry brands with very similar names. I've been caught more than once on this.
I have been pleased with some of the solids from Connecting Threads. There is not a full spectrum of colors but what they do have is nice. You also might want to consider some blender fabrics that are not true solids but read for the most part as solids.