Thread is a lot like shoes. Not everyone likes the same stuff. After experimenting a lot with thread I've come to the conclusion that I love Aurifil, Gutterman, Mettler, and Sulky (all for different things).
A lot will depend on what your machine likes as well.
You can try to experiment with some of the thriftier threads and if your machine likes them, then use them. My machine doesn't like them, nor did I.
A lot of people here on QB love Connecting Threads Essential line. I disliked it so much that I traded the whole lot.
Buy 1 spool of a few of the thriftier threads as a trial. Don't make the mistake I did - I bought 10 spools!!