I have used every brand of thread and have about every brand. I love trying new ones. InvisFil is becoming a favorite for my bobbin. Connecting Threads cotton and the new poly is very good for piecing. I have good luck using it for machine quilting too. Can't beat the price for it, it is my basic thread of choice. Aurifil is very smooth and I bought a lot of it when it was on clearance from
http://www.tristan.bc.ca/specials.html, it still is the best price for Aurifil and Mako cotton thread. I use Superior threads when I find them on sale. Superior has a new silk thread the is great for machine quilting. Sulky and Gutermann and Mettler are very good. Robison-Anton thread is nice and usually better priced then most. YLI has very good hand quilting thread and excellent silk thread. I love using silk thread for FMQ and applique. Glide from Fil Tec is my next best FMQ thread. Star is nice thread but it takes a spool adapter which is not worth bothering with when there are other threads that don't need one. Presencia thread is good but not easy to find on sale. The Coats and Clark metallic thread is the best I've used for not breaking. It sounds like I have a lot of thread and I do. All the pricey brands I bought on sale or clearance to try. Silk is my all time personal favorite thread to use.