The Berlin Diaries and A Single Man by Christopher Isherwood.

The first is written from Weimar Berlin just as the nazis are taking over, and about how people in every day life is reacting to that. The movie Cabaret is based on it, but in the original it's a gay man befriending a sex worker, not a straight romance. Same thing as
Breakfast At Tiffanys.

The other is about a middle aged gay man mounrning his passed partner, reading Ruskin conservative art history on the toilet and yelling at kids to get of his lawn. It was made into a very sexy and pretty good film by fashion designer Tom Ford, but the vibe is very different, and as a grumpy middle aged queer, I prefer the book.

His characters are more real than plenty of people I have met in real life.