Schmetz Microtex Sharp sewing machine needles (package of 5)
They are available in three sizes:
Size 60 for mock hand applique using sulky invisible thread
Size 70 for satin stitching using machine embroidery thread on fusible applique,
piecing with batik fabric, 
and mock hand applique if you have trouble threading a size 60 needle
Size 80 for general piecing