Good stories with rich worldbuilding always make me happy, but it doesn’t have to be speculative fiction.
Here’s an example of online storytelling that is wonderful (and has a powerful message or three).
Smokescreen is a free-to-play online game, made by some folks called Six to Start along with Channel 4. It has a very clever plot. And, as of the latest episode, it even has a resident music video (which is part of one of the episode’s puzzles).
It’s lovingly put together with the kind of attention to detail that pours out of the Grand Theft Autos and the Oddworlds of this gaming world.
Oh, and if you do start playing, my username there is quite predictable.