SF Game, maybe. D&D has it beat in the category 'all RPGs'.Originally posted by Mark G.:
Classic Traveller and other forms of the game is THE most versitile and imaginative SFRPG that's ever been published. It is second to none with D&D. No one expected it to last over 25 years and the ideas and adventuring are endless and it is The most widely used game in the world.
Now, is it the most imaginative? I dunno. SkyRealms of Jorune and a few others have advanced really interesting settings, to be fair. Some SciFi games have actually had really interesting premises and done a good job with their aliens and their technology and cultural interactions. But Traveller does rank in the top few, for certain, and is (I'd guess) the most widely read/played of the sci-fi RPGs, if you count all the variants together.