Sega's Virtua Processor: the one-hit wonder of cartridge-based video game enhancement chips
As a self-admitted "well-adjusted" Nintendo fan, I routinely take time to mine the fragmented memories and interests of my past via the realm of retrogaming, which is a stupid word. Lately I've been pretty into the "Sega Genesis," but more specifically its Japanese incarnation, the Mega Drive. One thing that surprised me when I first started really learning about the thing is that unlike the Nintendo systems I'm most particularly familiar with—the Famicom and Super Famicom—essentially no Mega Drive cartridges use any special hardware to enhance the functions of the game beyond what the system is capable at the base level.