I use Connecting Threads, Essential, 100% cotton cones. I watch for sales and buy a few at a time. I've found that I like it the best. Even though they don't have a lot of color choices in the large cones, I haven't had any issues with going with them. No matter what color my fabric is, one of the available colors of the large cones will go good with it. Or, if you use a lot of completely matching colors - they also have a huge selection of smaller spools of Essential. I prefer to use cotton thread and stay away from the poly.
I usually quilt/piece using basic colors, and use the antique color the most as I like my quilts to have that old fashioned look.