Hey, do you have a favorite thread? It's always seemed kind of silly to me to nitpick over which thread to use, but then I fell in love: with Mettler. I really adore their Metrosene variety, and more importantly, my machine adores it as well. This stuff glides effortlessly through my Bernina 1008 and makes beautiful stitches every time. (New Yorkers: you can buy Mettler at SIL Thread on 38th Street and City Quilter on 25th.)
Another thing to love: I've found that Mettler is smooth enough that it works well for basting and other hand stitches. Plus, it's a bit thinner than Gutermann silk thread, which makes it easier to thread through a small sharp needle.
So, how about you? Are you discerning about your thread? Or are you happy as long as it sews a stitch? If you're not really sure yet, it's always a great idea to try out a new variety on each project to see if one is match made in heaven . . . or just a short-term affair.