I love La Grisette. It's not posh but the food and service are excellent and the prices very reasonable. There's a varied menu, with something for everyone's taste. (The menus on the tables are in French but, if you weren't paying attention in your French lessons at school, there's usually a blackboard outside with everything in English).
As I've said, it's definitely not posh; it's just a typical street corner café really (
https://tinyurl.com/yanfevbf and
https://tinyurl.com/ydh2layn ) but it's worth seeking out if you want to find a place that's mainly patronised by discerning locals, rather than dishing out overpriced food to tourists
The address is 27 Rue du Faubourg du Temple, 75010 Paris. It's a 5-minute stroll from République Metro station, on lines 3, 5, 8, 9 and 11.