When we're talking about beef, tougher cuts of meat do well in a slow cooker. They are less expensive and create a more flavorful, fall apart tender end result. Think of chuck roast, rump roast, round steak, brisket, skirt steak, bottom round roast and ox-tail. Blade chuck, arm roasts or arm chuck, eye of round (not rib eye), short ribs and flank steak also do well in the slow cooker. Fattier and bone-in cuts tend to produce more flavor. If you don't have good fat marbling in the cut you choose, you can add one piece of oxtail or a beef shank or even one short rib to the slow cooker to help create the unctuous broth and deep beefy flavor you want.