I've been using Bottom Line (Superior) for a while and really love it. It plays well with whatever I use for top thread; I use it for both FMQ and piecing. What I REALLY like about it is that you can get so much more thread on the bottom than normal thread! I had the chance last month to take a class from Libby Lehman, who "designed" this thread ... actually, she told us that she gets to pick out the colors! And she did a good job, because they have a lot of nice colors to choose from.