On the south side of the river, Sauvage is a great spot where for less than €50/person you can have a meal in a casual setting that would cost twice that in a more formal setting. Great wine list too!
If you go to the bathroom in this place you have to walk through the kitchen and you’ll be left wondering how they can make this amazing food in what is possibly the smallest kitchen I’ve ever seen (smaller than an East Village apartment kitchen!!!)
The menu changes daily but I highly recommend the fois gras appetizer and the bonito appetizer. The place is famous for its sweet bread entre but the lamb is very good too!