It's amazing what influence D&D has made made for gaming in the fantasy genre, just like what Street Fighter II did for fighting games and what Wolfenstein 3d did for FPS games. If it wasn't for D&D, we wouldn't have had other tabletop games like Warhammer, Magic: The Gathering, Mage Knight, Dragon Dice, and numerous fantasy themed board games, as well as video games like Ultima, Might & Magic, Warcraft, Diablo, Elder Scrolls, and Everquest. All those games owe their existence to D&D.