I use the Aurifil 50 ct and have tried the Masterpiece 50, both on my Janome and my FW. It also worked well on my Pfaff.
For my LA, I have tried Omni, Glide, King Tut, and Aurifil Invisible. I have used Signature when I rented a LA at my old LQS. Signature was their favorite thread. I like the Glide along with the MagnaGlide bobbins.
I have used YLI for making pincushions.