Stackable containers that, in various embodiments, are adapted to be vertically and / or horizontally interlocked with other, like, containers to, for example, increase the stability of stacks of the containers. In one embodiment, a stackable container comprises: (A) a top surface comprising a shoulder portion that extends upwardly from the top surface and that is substantially disposed within a perimeter defined by the top surface; (B) a bottom surface defining a stacking recess; (C) a plurality of substantially vertical side surfaces that extend between the top surface and the bottom surface. In various embodiments, a recessed portion of the bottom surface adjacent the stacking recess is adapted to substantially mate with at least a portion of a shoulder portion of a like container.