There are three types of pork ribs--St. Louis style, spareribs, and baby back ribs. Compared to regular ol' spareribs (the biggest cut available), St. Louis ribs are a sight to behold—they're trimmed into a shapely rectangle by having the cartilage and rib tips removed. The meat they have is fattier and stays juicier than baby-back ribs. And because they've been trimmed down, they're thinner and flatter, making them easy to get uniformly browned.