My employer often takes us to La Sirène for our Christmas time office diner. He goes there often with his wife as well.
I must say, I'm very open minded food wise, so I'm willing to try many different things, and this restaurant doesn't disapoint! I've enjoyed their food immensely, especially the grilled octopus. Of course, being a large group, we get to sample many of their selection of appetizers, which they are all great.
If you're a fish fan, La Sirène is the perfect place for you! You can go in the "poissonnerie" and chose your fish or lobster.
Its a bit pricey for me, but I really enjoy it whenever I go with the office!