Michael Dummett, in his preface to the first edition of Frege: Philosophy of Language, says:
"I am always disappointed when a book lacks a preface: it is like arriving at someone's house for dinner, and being conducted straight into the dining room" (ix).
I agree, but I am also disappointed when a book lacks a good index: it's like having an enjoyable dinner with friends but then not being able to remember all the witty anecdotes.
The best example of an index entry I am aware of is the entry for "Hegel" in Terry Pinkard's Hegel: A Biography, which itself can function as a kind of super-abbreviated biography. I've reproduced a slightly abridged version of the "Hegel" entry below:
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