From Hemingway, A Moveable Fest, on a bad cafe:
The leaves lay sodden in the rain and the wind drove the rain against the big green autobus at the terminal and the Café des Amateurs was crowded and the windows misted over from the heat and the smoke inside. It was a sad, evilly run café where the drunkards of the quarter crowded together and I kept away from it because of the smell of dirty bodies and the sour smell of drunkenness.
From Hemingway, A Moveable Fest, on a good cafe:
It was a pleasant café, warm and clean and friendly, and I hung up my old waterproof on the coat rack to dry and put my worn and weathered felt hat on the rack above the bench and ordered a café au lait. The waiter brought it and I took out a notebook from the pocket of the coat and a pencil and started to write.
A collection of articles on good bistros in Paris:
The best bistros in Paris in 2019, according to Vogue:
https://www.vogue.fr/lifestyle-en/article/the-best-neighborhood-bistros-in-paris
The New York Times on six affordable Parisian restaurants in 2019:
https://www.nytimes.com/2019/04/10/travel/affordable-dining-in-paris.html
The top 100 bistros in Paris:
https://www.paris.fr/pages/paris-bistronomie-les-100-meilleures-adresses-de-la-capitale-4752/
The best classic bistros in Paris:
https://bonjourparis.com/food-and-drink/the-best-classic-bistrots-of-paris/
Below is an old article on the Parisian bistros in 2010 yet it could serve as a useful starting place for research. I hope in the passage of time that none of them have de-evolved into a Cafe des Amateurs. Perhaps some have improved with time.
https://www.saveur.com/article/Travels/The-23-Best-Bistros-in-Paris/