Crimson Longinus
Legend
I don't remember how they're mechanically, but I can see them being popular. They're plane-touched humans like you say, but at least to me they seem instantly cooler than aasimar which are basically angel-humans and it is hard to get lamer than that. They also are not so desperately edgy than tieflings (though I can respect desperately edgy.) They also are basically four races in one, as each element has their own themes. Whatever sort of character you want, it's likely some type of genasi would make thematic sense with it. I could easily see a setting where there was just humans and genasi and it would work just fine. Hell, even a setting with just genasi and no normal humans at all would work.I am honestly surprised people like genasi as they are badly built and are like the less cool middle child out of the plane touched humans.