The biggest concrete types of Harvard architecture devices I know of are some older small microcontroller architectures (e.g. the PIC10 and PIC12 families) and

The biggest concrete types of Harvard architecture devices I know of are some older small microcontroller architectures (e.g. the PIC10 and PIC12 families) and purpose-built DSPs (e.g. Analog Devices SHARC and TI C6X families). I'm pretty sure that some GPU shaders are also Harvard architecture, but I've heard that mainstream vendors have moved to a von Neumann model.