The Main factor.
Who can say which archaeological discovery is the best? Every country will choose something that belongs to them, like a historical legacy. But which factor is the main factor? Is it age? Or is it about host country richness? I don't think so.
The main factor is dirt. Isn't it funny? The more dirt you'll have on your hands, the more satisfaction you'll receive. Sure you can tell this is nonsense, but you be wrong. How can you think in that way, if you had never tried to do it. To dig up some ancient stuff.
Have you ever been to Olvia? Do you know anything about it? First of all, it is an ancient village on the blacks sea shore. And it is amazing how our predecessors were similar to people of ancient Egypt. Sure we don't have pyramids and we didn't have pharaohs, but it still was similar culture and similar gods in those ancient cultures.
Artifacts, which you can find in Olvia, are astonishing. Is can be simple plate, but with such bright painting, that you wouldn't believe in its age. Almost three thousand years. Or you can find a transparent vase, with glass thin as no vase has nowadays. I guess after such experience you'll be the most successful archaeologist in the world, and rest should admire you, you can think. But the main fact is still there. Our best discovery yet it's a fact that we are digging.