Facial hair suits some men, and then clean shaven suits the rest. Stubble is almost always sexy.
But the mustache by itself is not nice..nuh-uh. I've also seen this other interesting style that just doesn't work where the sideburns are thick at the top of the ear, and then thin out all the way to the jawline, which trails from one side to the other...like some silly black line on the guy's face...yeuch! Not pretty...