I learned a lot about thread, needles, and tension from Superior's website. It has a WEALTH of information and it finally made sense!
I've tested various brands and the only ones my machine did NOT like was Floriani and King Tut.
I use Connecting Threads Essentials for all of my machine quilting, and stock up on almost every color when it goes on sale - although even at full price, it's a great bargain. I will also use CTs for piecing on most quilts I make and give away.
But for those special quilts that require detail and precision piecing, I love to use Superior's Masterpiece. My machine seems very happy with Masterpiece and even seems to "hum" when using Masterpiece! Again, when it goes on sale, I stock up (mostly just use neutral colors).