I often see people ask questions in online forums about whether such-and-such is a 'good font', and hear and read lots of discussion about which fonts or typefaces are 'best'. The only way such terms make any sense to me is from a technical standpoint. If a font is missing many characters, or doesn't space properly (due to poor, or missing kerning), then that is probably a 'bad' font. Also, if a font is not an original digitzation of a typeface design, then that is a BAD (unethical) font.
However, I realize when people use those terms, they most often mean it in an artistic, or esthetic, sense. They are asking questions about taste and style. That is a much harder question to answer. It is common, and easy, to give an answer that says, essentially, that 'classic' typefaces are best. After all, they have stood the test of time, and have proven themselves useful for hundreds of years in most cases. Typefaces like Garamond, Baskerville, Bodoni and Caslon are called 'Classics' in most writing on the subject of Type. They have also helped us define our notions of what makes a typeface beautiful, whatever we mean by that. What makes them beautiful? It's not just legibility, because many typefaces can be clearly read, but would rarely be thought of as beautiful. Proportions, curves, contrast, strokes and other aspects of a type's design all contribute to what makes a typeface beautiful in our eyes -- and like other forms of beauty, it is really in the eye of the beholder.
It's interesting to me to read the words of experts from the past when they write about 'good' typefaces. It may show something about how much typefaces are like any other art form. Daniel Berkely Updike, whose book "Printing Types: Their History, Forms and Use" was considered worth re-printing almost 50 years after its last edition, said the following about type: "Horace Walpole said about people that nine-tenths of them 'were created to make you want to be with the other tenth.' This is true of types." He also says that "if we know the truth typographically we shall be freed from using many of the poor types that are offered us." His attitude seems to me to reflect a sort of snobbery that says that only a few typefaces are worthy of our use and admiration, although he does say that we should be "directed by taste and a sense of the fitness of things". To me, that is the key, because if a type fits its use then it could be considered good for that use. However, apparently in Updike's view all the good typefaces anyone would ever need were already designed when he wrote those words in 1937, because he further claims that "examples of almost every type that the world ought ever to have seen could be shown in a thin pamphlet", in contrast to the specimen catalogs that filled hundreds of pages with type samples.
In contrast to Updike's rather elitist view that only those who studied enough to learn what typographic 'truth' was could decide which types were 'good' (and implies that they've already been created in the past), Robert Bringhurst, author of "The Elements of Typographic Style" says "Typography, like other arts, preys on its own past. It can do so with the callousness of a grave robber, or with the piety of unquestioning ancestor worship." It seems to me that Updike might fall into the latter category, along with those who think the world really needs another version of Caslon, Garamond, Bodoni, or some other 'classic' typeface. We all know the 'grave robbers' who just copy from the works of others. In their best light, they might be those who revive lost works, especially if they credit their sources; in their worst form, they steal the work of others and try to claim it as their own work. Bringhurst at least allows that these are not the only two possibilities when he says that typographers (including type designers) can make use of the past "in thoughtful, enlightened and deeply creative ways." This is the opening for new type designs, that create works of art from the symbols we use for communication, so that "ancient forms are living in the new" in Bringhurst's terms.
So how are we to decide what is Good, or Best (since we love superlatives)? I think both of these authors agree on the importance of knowing the history of type, but ultimately you have to be the judge, relying on your own (hopefully informed) taste, and feelings about whether the type suits your material. I think 'Good, Better and Best', are context-dependent terms, and it's up to your judgment how well a typeface fits your particular context. One thing Daniel Updike said that I can fully agree with is that "It is a simple matter to make lists of good types -- though not as simple as it seems. It is still simpler -- and much less trouble -- lazily to accept other people's conclusions and think no more about it."