I was wandering around rpg.net and ran across Sergio Mascarenhas's excellent review of Chaosium's 1989 roleplaying game PRINCE VALIANT, THE STORYTELLING GAME. I regard this game as one of the very best examples of how to write a game. Simple rules that are flexible and widely applicable, excellent presentation, and outstanding setting material all combine to make a wonderful game and one that is very good for introducing roleplaying games to new players. It's a pity it was unsuccessful commercially and will never be reprinted, but it's hard to know what to blame for that failure. Was it a failure of marketing? Limited distribution? Limited interest?
[2019-11-10: What do I know? It turns out a new edition was kickstarted in 2016, though they were still fulfilling things in 2019.]