When it comes to Parmesan cheese, bags of pre-shredded Parmesan lie somewhere on the quality spectrum between the cardboard tubes you pick up at the gas station and the imported hard wedges you grate yourself. A few cheese varieties similar to the classic Italian hard cheese also come pre-shredded. In addition, if you're willing to do your own shredding and grating, you'll find plenty of decent Parmesan taste-alikes if you need a substitute.
Grana Padano, a hard cheese, is considered quite similar to Parmesan. It is less expensive and more mild. Romano, another hard Italian cheese, is also frequently compared to Parmesan, but cranks the sharpness and saltiness factors up a notch. Interestingly, three different animals -- sheep, goat and cow -- are responsible for the three best-known Romano varieties: Pecorino, Caprino and Vacchino. You can find bags or tubs of pre-shredded Romano cheese in the dairy section of some supermarkets and delis.
Two hard cheeses from Switzerland each have ancient origins. Sapsago is low in fat because it is made from skimmed cow's milk. An expensive cheese, sapsago gets its distinctive green color and spicy flavor from a local clover used to infuse the milk. You'll also spot the finished cheese by its silver foil packaging and conical shape. Sbrinz is revered as one of the oldest cheeses in Switzerland's history, going back to the days of ancient Rome. It is an extra-hard cheese, with a mellow taste and tangy undertones.
You'll find pre-shredded Asiago and Monterey jack in tubs or bags at some delis and supermarkets, as well as in whole form. Asiago is a hard cheese that hails from Italy, but versions made in the U.S. are comparable in quality to more expensive imported versions. Asiago is a bit sweeter than Parmesan. Created in California, aged Monterey Jack can sometimes pinch-hit for Parmesan. You may also see it sold as "dry jack." Monterey Jack is less salty and milder than Parmesan. The aged version is especially appropriate when you need a gratable cheese in the mode of Parmesan, but geared to Mexican seasonings.
Despite its clinical name, nutritional yeast is a flavorful option for people who can't eat dairy or who prefer not to use animal products. The deactivated yeast has a salty, deep flavor similar to Parmesan. Its texture is more comparable to finely grated Parmesan than to shredded cheese. In situations where that doesn't matter, sprinkle nutritional yeast as you would grated Parmesan. It works well sprinkled dry over pastas, pizzas and popcorn, or blended into dressings and sauces. Alternatively, look for faux Parmesan products made from soy milk.