A few personal favorites (I’ll try to keep the list updated).
Fish Lab Boissonnerie - An English titled fish restaurant in Paris. Casual, but cool crowd. Great fish (obviously) and good vibes. Seems popular with the expats, acting local, and desperately hoping to not be mistaken for tourists. That makes it sound worse than it is. Good choice for a meal with friends. Link
Breizh Cafe - Bretonne crepes made by a Japanese chef. What could go wrong? Nothing. They seem to be expanding, both in Paris and internationally, but I prefer eating at the one communal table in the deli extension in the Marais (they call it the Paris Grocery on the website). Go with a friend, so you can share two savory and end on one sweet. Link
Rose Bakery (and cafe) - The original Rose Cafe and bakery. Simple. Great. Simply great. They also have branches at some of the Dover Street Market stores, but this is the original one. Great cook book also. Link
Tiki Bar Dirty Dick - There is nothing a hipster loves more than a tiki bar in a formerly seedy red light district. Run by Americans. Or Australians. Or whatever. They have beards and tattoos. Great drinks also. And there is a good bar with a tiny dancefloor across the street. You can go back and forth. Link
Berthillon Ice Cream - Perfect refreshment during a long stroll across Paris. The lines are always long, but it’s fun watching people in crazy anticipation (and trying to decide which of the amazing flavors to try). A bunch of other places, some nearby, sell the same ice cream, but somehow it’s better if you wait in the longest line at the original place. Link
Le Jules Verne - Haven’t been, and I’m sure it’s ridiculously overpriced, but how could a gourmet restaurat on top of the world’s most iconic tower not be amazing. Apparently Jean Paul Gautier’s favorite restaurant. One day! Link