OK, I confess; I'm not the world's greatest oyster conneseur, much lest raw oyster lover. Nor do I take pleasure in spending great amounts of money on a single meal. So last year I was in Bayeaux, France where I had the most sublime plate of raw oysters ... tasting just slightly of briny seawater and in a vinegarett of some sort, I fell in love with oysters and determined that if I ever had the chance to go there again, I would, if for no other reason than just to eat oysters. At this point I should say I was staying at a RS recommended inexpensive hotel where two American couples were trying to one-up each other as to how much they were going to spend on dinner that night. After the braggadocio maxed out at "no more than $500" and the gladiator teams each retreated to their respective dens, I asked the hotel owner for the name of a good restaurant, not expensive - no more than $30 or so. I don't remember the name of the restaurant, but it is located on the corner just across the street south (I think) of the cathedral; right the square. I had one of the best dinners of my life, thanks in no small part to the oysters that I ordered only because I believe in eating local foods, and rhey were local. A wonderful meal with a majestic view; it was a magical experience thanks to the plat de jour at a restaurant that put love into their food. So my question is, despite having taken the "long road" of getting to it,... Can I expect good to get oysters if I order them in Paris? Strange as it sounds, I've never ordered them there but have read about them being served. Is it appropriate to order oysters only, sans a full meal? What is oyster etiquette? Seriously...?
Here's a list of the 5 best restaurants for oysters in Paris posted by Paris by Mouth: http://parisbymouth.com/five-great-places-for-oysters/ Or go to a large brasserie, one with the oysters on ice out front. You can certainly order a dozen raw oysters and a glass of white wine. These large brasseries, such as La Coupole in Montparnasse, specialize in a plate of oysters and white wine. As Julia always said: bon appetit.
If you like oysters, the best place to taste them will always be on the coast. Paris is not on the coast. That said, I am sure that anyplace Bets recommends will be good.
I recommend you Le Bar à Huitres, in the 5th arrondissement! They are very nice and you'll be at ease enough to ask whatever you want about oyster, people are generally rather eager to explain all about their food !
more information: http://www.petitfute.uk.com/restaurants/seafood-fish-restaurant/le-bar-a-huitres/e-234105.html
Good suggestions here so far, but I'm going to refer you to Chowhound, as well. Folks over there know their food stuff, and are VERY specific! That being said... my husband is an oyster fiend. Cannot get enough, will order them just about anywhere. And yes, you can definitely get excellent oysters in Paris! It is perfectly acceptable to order just a plate of oysters, and in the winter, quite a few bistros (even smaller, very local places) offer not just a plateu des fruits de mer, but an "oysters only" platter served the same way. Get a basket of bread (or better, order pain de seigle - rye bread) some butter and a glass of crisp white wine - the oysters will likely come with lemon wedges and sauce mignonette - and go to town.