I use Sulky and Floraini, but also have used other brands good brands, most you can find at the place where you purchased your embroidery machine. Some threads you will find will break a lot, not sure why that is.
I also used the prewound bobbins in white, they work very well unless you want something to be two sided, then use the thread that matches in the bottom.
If you are using a pattern like Redwork that you can used all one color that is great,but to have to change bobbins every time you change top thread is a pain. For the most part no one is going to see the under side of your embroidery.
I do have some of the unraveling threads also, I think I got them thru Ebay, may have come from China, the colors are great, but they are much finer thread.
I watch for the sales on Sulky thru Joanne's when they have 50% off, but they don't have a lot of colors.
If you PM me I will send you some places where I have got various colors of thread and some of the brands you will not
know, but the thread is good. I have all kinds of thread in all kinds of colors.