If we stick to "economics" without even going to "well-being," I think median net worth is the best bet. But you know, governments find it easier to "book" corporate profits as part of GDP and call it a day.
On the more economic side, you have something like the Misery Index and its extensions (http://www.cato.org/publications/commentary/misery-mena). Obviously composite indexes like these have their flaws too, but overall they are more comprehensive than GDP alone.