* The Megadrive plus MegaCD plus 32X, affectionately called "The Tower of Power". I have one and it is quite a hefty beast.
* Sonic & Knuckles with its lock-on technology that allowed plugin Sonic 3 (or Sonic 2) to form the full game.
* Virtua Racing and its SVP chip, Sega's answer to the SuperFX.
* The Saturn and its extension cartridges that provided additional RAM.
* The Dreamcast and its VMU.
* The Megadrive plus MegaCD plus 32X, affectionately called "The Tower of Power". I have one and it is quite a hefty beast.
* Sonic & Knuckles with its lock-on technology that allowed plugin Sonic 3 (or Sonic 2) to form the full game.
* Virtua Racing and its SVP chip, Sega's answer to the SuperFX.
* The Saturn and its extension cartridges that provided additional RAM.
* The Dreamcast and its VMU.