I buy a lot of my thread online or at my LQS, no other place near me has decent thread. For my machines (Viking and Bernina) both Gutermann and Star (made by Coats & Clark) give off a LOT of lint and require me to clean my machine often. I haven't had a problem with any other thread so far.

Coats and Clark is not a quality thread - I worked for a Viking and Bernina dealer and he cautioned people that Coats and Clark will "fuzz" and be very hard on your machine. It also breaks easily due to how it is made. Mettler is my favorite but when I can't get it Gutterman gives me no problems either.