The fastest hedgehog in the world raced onto the Sega Mega Drive in 1991 and it instantly became a massive hit. Now, 18 years on and still a big hit, Sonic The Hedgehog is celebrating his 18th birthday (I doubt he’ll celebrate by going down the pub to get smashed). Since his release in 1991, Sonic has become well known all around the world for his attitude and his face paced gameplay. This has lead him to rack up over 50 million game sales. To let gamers celebrate this occasion, Game.co.uk has set up a special shop page featuring all the sonic games and gear that you can buy. This shop page features the latest games such as Sonic and the…