I am devoted to Bottom Line 60wt poly; it's a bobbin thread but I use it for virtually everything: hand piecing, hand applique, machine piecing, machine and hand quilting.
Always in the bobbin regardless of which machine I'm using.
http://www.superiorthreads.com
My Jems don't take it on top, so I use Aurifil 50wt cotton; it's a great machine piecing thread, because like Bottom Line it really irons seams flat.