I would say Poland, followed closely by Greece, Persia and Siam.
Because, unlike other features, which can be (more) powerful under the right circumstances, those features are good regardless of map.
- Zulu: Military powerhouse on Pangea, less so on archipelago. Only XP bonus stays with navy, but I prefer movement of England hands down.
- Polynesia: Cultural powerhouse on Archipelago, but crippled on Pangea.
Many other civs suffer in a similar way, even when not at first glance. Religious spread is hindered on small islands (plus the wide empire which favors religious developement and other boni like China and Mayans), Continents and Pangea make early conquest easy both ways.
So my choice of Civ for an absolute random map is Poland, because they profit no matter what. Persia is similar in mechanics, though not so strong. Because CS are so powerful since BNW, I would have placed Greece on top, and Siam third, if not for Austria and Venice, who can remove CS from the map. Else, having CS's as allies rules, especially coming into age of WC, and no civ is better at allying with and keeping them than Greece. And diplomatic Victory is hands down the cheesiest win in BNW.