I never paid much attention to threads until I started long arm quilting. For most of the last 40 years I've been using Dual Duty.
Recently I was given a modern machine with the advice that it likes Aurifil. So do I and so do the rest of my machines!
I recently got a cone of Superior's So Fine to use for machine quilting, haven't yet but next project I start I will be using it in the piecing to see how I feel about it.
With my vision issues and since I mostly work scrappy I pretty much always use a steel/slate blue and beige threads, one on the top and one on the bottom. Can't see thread well enough if the color matches to take it out...