I've only been in Montmartre a couple of times in the last 10-15 years, it's a bit of a blind spot along with many parts of the east side.
You have to check out the left bank, the 6eme is the nicest neighborhood in town, with lots of bookstores, rep theaters, good atmosphere. For cheaper eats, there is a good creperie with a selection of boutique ciders from brittany in one of the small roads off blvd St Germain (just past Rue de Bucci, which is a great spot with plenty of nice shops and cafes)
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If you want to have a parisian steak-frites, l'Entrecote a block west of St Germain church, 20 rue st Benoit but it's pretty crowded on weekends if you don't go there early. This is a newer outlet but it looks the same as the older ones and the service is very good (as are the house reds and desserts)
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