There has been a Photoshop contest over on Gizmodo, the theme being "what if games consoles had been around for hundreds of years?". Aside from the Call of Duty and Guitar Hero remakes, there were some Sega-related ones.
My favourite was "Crazy Horsey", a play on Crazy Taxi. Presumably you must ride your horse around the village, taking peasants to their chosen destinations (such as the gallows).
The next one wasn't exactly Sega-based, but was apparently made for the Genesis. With a name like "Grand Theft Wheel 4", that's the only console it could be made for, although the box says it's available on Mega Drive too.
Click here to see the rest of the entries. "Grand Theft Horse" is definitely the best.
[Source: Gizmodo via Kotaku]