In Rex Stout’s Champagne for One, Archie Goodwin attends a party and is warned that one of the attendees is carrying poison and might kill herself. The woman dies shortly after, and though Archie couldn’t prevent it, he can swear that he was watching her and she did not put the poison in her own glass. Since his evidence is all that turns a neat suicide into a messy murder, this naturally fails to endear him to everyone at the party (and some people outside it, too).
I re-read this over a few breakfasts in New York City last weekend, more because I had it on my Palm than because I’d chosen it as a New York-specific book. I rather like this one, as it has some fun detecting sequences. Others may have less favorable reactions to it, particularly if they find Archie annoyingly sexist: the dinner is attended by selected graduates of a charitable program for unmarried mothers (this is the 1950s), which gives him some opportunity to discuss the women—though, now that I think of it, not really much more than usual, unless they’re off in the wilds somewhere. (Archie doesn’t bother me; I never get the sense that he thinks less of women because he has opinions about their looks. I’m aware this opinion is not universal, however.)
As I recall, the A&E TV adapation of this book was also quite good.