Obviously spaghetti works really well at holding carbonara sauce, but I actually prefer short chunky shapes like rigatoni where it has a chance to get inside the holes, along with bits of anchovy (or pork). In these pictures I've used pennoni which is a slightly larger form of penne. This is 'lisi' pennoni which means it is smooth, but if I'd had any in the cupboard pennoni 'rigati' would have been the better choice because it's ridges would have helped the sauce cling better.