I am devoted to Aurifil 50 wt cotton thread (or Presencia 50 wt cotton) on top for machine piecing and Bottom Line, a very thin 60 wt Superior Threads poly, in the bobbin
I use Mettler cotton embroidery 60 wt for hand piecing
Connecting Threads have lovely colours, but are way too linty for me.
The only machine needles I use now are titanium 12s from Superior Threads