It depends on what your machine likes. My machine won't sew Coats and Clark Dual Duty at all but she has no issues with any other thread, including Coats and Clark Star Variegated. I generally use a 50/3 cotton thread for piecing (in neutral colors) and quilting (in colors to match or contrast- depending on how I feel). I do have some polyester thread that I plan to use when the color fits. Cotton thread is a bit more linty but it doesn't bother me. My brands are Connecting Threads, Superior, Madeira, Guterman, and probably some others. I ALWAYS get mine on sale as threads can run up the bill.