I was amused by this article by Emily Gould offering do's and don'ts for author acknowledgment pages, although I must note that some of her tips (e.g., "Rule #2: Don't thank a deity") seem more broadly applicable than others ("Rule #7: Don't swing madly from throwaway jokes to forced gravitas").
Personally I judge the acknowledgment pages in books I've worked on based solely on how effusively the author praises me. More effusive = better, in case you are wondering--although in my experience the level of authorial thanks I receive tends to be negatively correlated with my actual role in enhancing the book. When I do little but spruce up the grammar and correct a misspelling or two, I generally get warm accolades; when I transform an unpublishable mess into a clear, interesting read, I often get tepid thanks or none at all.
In retrospect, of course, that's not surprising. The dentist who discovers I have half a dozen cavities and spends three hours fixing them all does me more good than the one who gives me a quick, painless cleaning--but I certainly don't savor the process. So I guess that when I tear apart and rebuild someone's painstakingly crafted manuscript, it's unreasonable of me to expect gratitude. Yet of course I do, such is human perversity.