I agree with buying single cones of different types and finding the ones that both you and your machine like best. My Gammill seems to like King Tut or SoFine best(but different size needles and tension settings); YLI is ok but I sometimes have top tension problem, and while I like the look of Glide on some(too shiney on some)quilt, I have to use a thread net on it and find that the ends fray, so have to be aware of that. Bottomline is good in the bobbin when you don't want to change bobbins often!