My car originally came with literally an 8-ball crammed onto the shifter...after a few weeks it wore out and spun.
But for the last couple years ive been using a knob I lathed myself from a piece of aluminum bar stock. Only problem is keeping it polished. Its also pretty light, which I like on my tall yet short throw shifter.
Bad pic but its all ive got.
A friend of mine has made several from steel stock, trying to make them big and heavy..we put one on that we nicknamed "the beer can" and my damn shifter kept trying to pop INTO and out of gear when id hit bumps. it was seriously 3" tall.
The "mini-can"