Mary points out this site, which is taking votes on the "New Wonders of the World". The whole "Seven Wonders" concept has been applied in a lot of ways, actually: here's the Wikipedia page, which lists a number of such lists, starting with the traditional, and probably most famous, list of the Seven Wonders of the Ancient World.
But all of these kinds of lists always revolve around built things, don't they? How about made things? How about Seven Wonders of the Artistic World? I'm going to think this over a bit. Maybe after the hiatus I'll have something to say about it.
(Lots of other good linkage at Mary's post, by the way.)