Blunt-pointed needles are best for working on most cross-stitch fabrics because they slide through the holes and between threads without splitting or snagging the fibers. A large-eye needle accommodates most embroidery threads. Many companies sell special 'cross-stitch' needles, but they're identical to tapestry needles; both are blunt tipped and large-eyed.
The list below will guide you to the right size needle for the most commonly used fabrics. One exception to the blunt-tip needle rule is waste canvas; use a sharp embroidery needle to work on that fabric. Working with seed beads requires a very fine needle that will slide through the holes. Either a #8 quilting needle, which is short with a tiny eye, or a long beading needle, with a longer eye, will work. Some needlework shops also carry short beading needles with long eyes.