Tailor-made or modules? Sandbox or railroad? Neutral or player-friendly?

My experience is that the best game a DM can create is usually the kind that that particular DM enjoys and understands and relates to.

And the measures of how good it is will be are none of the above categories. There can be excellent and poor neutral DMs. There can be exellent and poor player-friendly DMs, Excellent and poor railroad quests, excellent and poor sandboxes, etc.

The true measures of how good the game will be are how good the DM is, how well she communicates with the players, and how well the players can enter into her approach.