I'm familiar with many fine vegan cheeses, ranging from cream-cheese to Camambert. Undoubtedly much progress has been made in this area in recent years. The one (important) cheese I have yet to find a suitable replacement for is Mozzarella.
More specifically, I'm interested in a vegan cheese substitute which successfully mimics both the flavor and texture of melted Mozzarella. All soy-based substitutes I've tried which did have stringy properties suffered from very high stickiness, and adhered to the roof of the mouth resulting in an unpleasant experience.
Another recipe I've tried is cashew based cheese combined with tapioca flour, though both flavor and texture were less than adequate.