[Shawn]

This is all too subjective really, but you might be able to come up with some sort of weighted score that indexed total height, median height, bleacher effect / tiering, natural setting, night lighting, style and era representation, plus some sort of pizzazz intangible score. I don't know how you'd take "clusterization" in to account or whether to penalize or reward nodular skylines vs. one central clump. Again, it's all pretty subjective outside the height stats.

My favorite American skylines are Pittsburgh's and Seattle's; I enjoy looking at them as overall aesthetic units even more than I do NY or Chicago. On the flip side, I don't enjoy Miami's skyline at all, because I don't like skylines predominantly made of residential with exposed balconies. Outside of natural setting, neither Pittsburgh nor Seattle would score near the tops on any of the possible indexes I listed off above, while Miami would score better overall and even score highly on natural setting. So my own ranking system wouldn't accurately reflect my favorites.