The types of rices used in making risotto have the ability to absorb liquids and to release starches which in turn make them stickier than long grain rice. The varieties include Arborio, Baldo, Carnaroli, Padano, Roma, and Vialone Nano. Carnaroli and Vialone Nano are considered the best and are generally the most expensive. With Carnaroli, there is a smaller chance that it will get overcooked whereas Vialone nano will absorb flavors better and since it is smaller, it will cook quicker. Roma, Baldo, and Ribewill not be as creamy and are better for soups and stews; I personally have not seen these varieties in the stores. The three varieties that are most common from cheapest to most expensive are Arborio, Carnaroli, and Vialone Nano. Arborio is what is most commonly sold and is great for a traditional risotto. You will sometimes see the boxes labeled Superfino, Semifino, and Fino, these designations describe the size of the grain and not the quality of the rice.