Kaguya. A civilized, proper princess, with a lack of practical knowledge, a penchant for spontaneous projects, and a habit of trolling and killing the hell out of Mokou to stave away boredom. Plenty of things to do with that that don't involve World of Warcraft!
Marisa. As I've said before, she is the one character in Gensokyo with literally no superpowers. All her awesome magic? She got it through dedication, hard work, and complete disregard for the concepts of property and exclusivity. She does care about people, yes, CoLA and the fairies manga bear this out. But like the other magicians, her goals, such as that huge immortality pill of hers, come first. She's smart, smart-assed, prideful, easy to frustrate, and has no concern for her infamy, yet refuses to ditch the broom because that's how witches do it. This is an actual character right here. Reducing Marisa to "spark everything, ship everyone" is almost criminal.
Everyone in PCB. Seriously. Even Lily. You know you're doing it wrong when you mess a character as simple as her up. Yes, you can shoot me for shipping her with Yuuka. But yelling about spring has taken the place of the fact that she literally IS spring, which is something that is much more interesting. Don't even get me started on the Yakumos and Hakugyokurans...