The interesting places to find new archaeological sites are places where we know there were lots of people nearby, and where for some reason human habitation ceased and the sites were preserved.
I hold some hope for new methods of underwater archaeology to uncover sites on the southern coast of the Black Sea and in the Persian Gulf. The latter especially because it was vast, rich floodplain during the last glacial maximum, and the oldest known true cities sprouted into existence on it's northern shore pretty much instantly after it flooded. I like to think that the oldest city ever built lies submerged in mud and water somewhere in there, just waiting to be found.
(Not that there would be necessarily much to find anymore, they probably didn't build out of rock.)
