Try a variety and see what you like. Just because a thread cost more doesn't make it better. If you have a quilt show you can go to thats a good place to buy thread at a good price. I use Aurifil; my favorite for piecing. It's low lint, strong and since it's only two ply when I have a lot of seams in a block my block comes out to the right size more than when I use a 3-ply thread. I also use Connecting Threads thread and have had no issues with it. I have an embroidery unit too and for that I use Sulky, RA, Jenny Haskins, Floriani, Prencia, and a few others. I wouldn't buy a low grade thread to make something that I wanted to last. I have lots of thread that is really old and I use that to hand baste or on my machine when I'm practicing on something or testing out stitches, trouble shooting. I know that some have said that their machines don't like certain threads, I've not had that experience. I figure if I own a 10,000 machine it should take what ever thread I give it and my Ruby did and my Viking Diamond Deluxe does. I thought I had issues with the cone thread once and after pulling my hair out, I finally read up on it and changed the size and type of needle to the project that I was working on and it went well after that. Just buy what you can afford and test them out. With sewing machines like other things in life; what works well with one person/machine may or may not work with the next one.