Definitely stone. With a realistic shot at Stonehenge/Great Wall/Pyramids, any one of them can really get your game off to a good start. Early Maoi Statues is sweet too, but often I want to save that for a 1-tile island or the like; only if my capital has hardly any land tiles will I build Maoi early.
Marble is great of course, particularly for the Great Library, but a lot of the other marble wonders just aren't as useful as the early stone ones. Temple of Artemis perhaps being the exception.
Marble is great of course, particularly for the Great Library, but a lot of the other marble wonders just aren't as useful as the early stone ones. Temple of Artemis perhaps being the exception.