I like a crusty, hearty bread with a lot of texture. A sourdough bread would be an excellent choice, as would a hearty rye, French baguette, or a dark pumpernickel. Bread that has been cubed (or torn) into bite-size pieces works best, even better if it's a little on the stale side! If needed, pop the cubed or torn bread into a low oven (300 degrees Fahrenheit) on a baking sheet for a few minutes to remove some of its moisture.