The answer seems to be yes and no! Yes it is the best according to God's nature and plan. No because value and worth comes from God. Something can only rightly be called the best ( e.g. any given possible world) because God makes it the best. There is no "best making properties" in possible worlds in which God chooses the one that has the most of such properties. Rather, God creates the world by His nature and plan. We must keep in mind, it is He who states if something is the best (if it exemplifies His nature and what He thinks is best). God has not revealed the actual world is the best. Therefore, we must not conclude it is or is not. However, we do know God is not obligated to always and only create the best. In fact, it is quite possible He may create something that is not the best (a world with deficiencies) to all the more demonstrate Himself as the best. John Frame commenting on evil says,
"People sometimes say that God must make the best possible world because he himself is perfect. So they think that although evil exists now, this is nevertheless the best world God could have made. That is one traditional attempt to solve the problem of evil.
I disagree, however. Genesis 1:31 says that God made everything good, but not perfect. “Perfect” would mean not only good, but also incapable of becoming evil. Clearly God did not choose to make that kind of world. In that sense, the new Heavens and the new Earth (Rev. 21:1) will be a better world than this one, for that world will be confirmed in goodness, incapable of becoming evil. So the world in which we presently live is not the best possible world. God is free to make a world that is imperfect in some respects.
Could God have made a better world than this one? Certainly. He could have made what we call the “new Heavens and new Earth” right back at the beginning. Why, then, did he choose not to do so? I don’t know. That is essentially the problem of evil. I think there are some biblical ways of addressing the problem, but I don’t think we will have a completely satisfying resolution of the problem during our present life."William Lane Craig discussing the Ontological argument writes,
 Helm, Paul. The Eternal God: A Study of God Without Time. 2nd ed. (Oxford: Oxford P, 2010) p.p.186-188.
 John Frame Interview on the Problem of Evil Here
 William Lane Craig. Question 51. Here