I enjoy storytelling games. They are the only medium in which no-one, even the tellers, knows the outcome of the story. Usually, they involve players taking on the roles of protagonists, with a storyteller who takes on the role of the antagonists and other characters. They exist in a space between improvisational theatre and tactical wargames, with players at both ends of the continuum. I flatter myself to think I play nearer the "impro theatre" end.
I enjoy my sci-fi TV, and happily use settings that everybody knows and do not require me to reinvent the wheel. For a Star Trek story, I helped set up a science fiction society in the University of London. The site for the ongoing series Star Trek: Colony describes these games as well as an ongoing saga of tenuous alliances, broken hearts, mystical cults, and twenty-fourth century science. of As if that wasn't enough roleplaying, I also admin Who-rpg, the mailing list about role-playing gaming based on Dr Who.
With Fred Hick, John Morrow, and Lee Valentine, we surveyed how folk use adjectives and wrote an article on Choosing Natural Adjective Ladders for new games which, like Fudge or Castle Falkenstein, use them.
During my PhD, I was deeply into online massively multiplayer storytelling games, all of which seemed to be in the same dark gothic world of Werewolves and Vampires. These included GarouMUSH, adminning Storyteller's Circle, and creating an extensive database of information on Ireland for a game set in Dublin. I also wrote a conversion script to turn MUSH help screens into web pages. In a moment of weakness, I even co-ordinated a document on various attempts to pseudo-realistically explain the genetics of werewolves. But then real life took over.
Nowadays, I am a great fan of the Fudge System. Character descriptions are written in plain English. The rules for including the random element in stories are extremely simple. My Fudge pages include information about my Middle Earth campaign.