When the trifecta of writing quality, mental vision and in-context achievement make something that stands out. I can decently carry one and even two at any given time, but there are always flaws. The best I can expect is nailing it fully on one or two. All three is a moment that goes beyond the magical unicorn of satisfying conclusion to a long term roleplay. I've had those, but I don't anticipate them. Instead I get little kicks from episodic or 'scene by scene' plays that strive against bogging down in something people aren't mutually interested in.