The 16-bit era was the SNES, the Sega Megadrive (or Genesis), and the PC-Engine (or Turbografx-16), The Neo-Geo doesn't count as it was not intended to be a direct competition on the other 3, it was not available everywhere, it was a 1:1 arcade port, and the price was put for selling at a profit in a low volume, it was an elite system for a few people...
The PC-Engine was powerful compared to the NES, but compared to the other two it lacked a lot, it had a 8-bit CPU with a good clock speed, and it was really crippled on inputs and outputs. The Genesis had the clock speed, faster than the SNES one, but the SNES won with the CPU-architecture, sound capabilities, the amazing Mode-7 and the inclusion of the enhancement chips, the two most famous were the Super FX and the CX4...
So bottom line, the 16-bit era was the only one where the selling ranking was on par with the console power... Super Nes 1st overall, Genesis 2nd overall and Turbografx 3rd overall...
