Pokemon? Avatar The Last Airbender?
I know this was over a year ago, but Avatar: The Last Airbender would actually be fairly easy. We could simply shoe-horn rationalist values onto the personalities of the four elements.
Fire: Tsuyoku Naritai and The Arrogance of Einstein: they are a proud, ambitious people, who know what they want, and push hard to get it, who know their strengths and dispense with cloaks of modesty. They are highly consequentialist, and are not at all risk averse, preferring 50-50 odds of glory or ruin to 100% chance of modest prosperity. They understand the value of inspir...
I've been enjoying reading Less Wrong fanfiction, and I wanted to suggest another fandom that should have at least one rationalist fanfiction: Mage: The Awakening. It's a roleplaying game about "modern sorcery." My description can't really do it justice...