My go-to is SoFine #50--it's a non-shiny poly. I also like PermaCore and for very dense quilting, MicroQuilter. If I can't really decide on a thread color due to the fabric, I use Superior MonoPoly (clear or smoke). I also like Glide for a little more "bling" to the thread. I've also used YLIcotton and King Tut--but find cotton pretty linty and sometimes when I'm moving pretty fast, I have trouble with breakage. I also use a #50 trilobal Marathon in "old" gold and a silver white and really like the outcome with both.