SoFine #50 with white-ivory-grays being my standard colors of threads. Glide, on occasion, but have to change the tension which I prefer to leave alone. I only buy new thread colors as I need them.

i have a ridiculous thread stash so i try to use whatever i have that will coordinate with the top.

if i ever manage to re-home enough thread to truly need more, i might try the glide so many recommend.
a friend of mine swears by isocord, too.

Glad someone else has my problem. We were unpacking some boxes and my DGS was stunned when we opened 2 boxes of thread -- now I have to find places for it since these boxes (labeled quilting books) were hiding for 5 years and I have bought more as I needed it in the mean time. LOL