A few examples:
--GEAUX SAINTS! Any French person will pronounce this phonetically as "Zho-Saints." The "e" turns the "g" soft in French. So if you want a hard g, as in "GO," you have to get rid of the e: "GAUX SAINTS!" (But I don't think anyone is going to put a Sharpie to their bumper sticker and strike out the e just because I say so.)
--Fleur de Lis. People here pronounce that "flure duh lee,"' on the assumption that the French never bother to pronounce final consonants. That's generally true. However, out of sheer cussedness, the French make an exception for the occasional final consonant, and "lis" is one of them. French pronunciation: "Fleur de Lisss." I persist in pronouncing it that way, even though I get pitying looks from the locals who assume I haven't lived in this former French colony long enough to learn proper French pronunciation.
--"Laissez le bon temps roulez," and variants, like "roulé". First off, this literal translation of an idiomatic English expression is laughably meaningless to a French speaker. Second, if you must use it (and in these parts, we must), at least spell it right. It should be "rouler" (infinitive) and not "roulez" (second person plural). But these subtleties are of no consequence to New Orleanians (or their Cajun cousins to the southwest) and I don't expect to see a sign painter correcting the moniker of the "Bon Temps Roulé" cafe a block from my house any time soon.
--Then there are those who think that by adding a nifty-looking accent to their names, they will give themselves a certain continental je ne sais quoi and perhaps even get invited to the Bastille Day (quatorze juillet) reception at the French consulate. Example: the grocery chain "Robért." Robert happens to be a common French name, used both as a surname and a family name. It is never written with an accent. The gratuitous addition of an accent over the e immediately signals to a French speaker that this "Robért" person is an illiterate or an imposter or both. Then there was the case of the late Congressman F. Edward Hébert, who insisted, because it looked cooler to him, that the accent in "Hébert" was grave (è) instead of acute (é). That was orthographically and phonetically incorrect. But whenever anyone pointed that out to him, he said it was his name and he could write it any way he damn pleased.
Maybe that's the bottom line (la ligne la plus basse): this is our city, our cultural heritage, and we can write and pronounce it the way we want no matter what the Académie Française thinks about it. (Frankly, they don't think about it much.) Fair enough. After all, the French have been massacring English words ever since 1066. In France today, "sweat shirt" comes out "sweet shirt" and "Levis" become ""Loo-wees." And so on...The battle is hopeless on both fronts, so probably the wisest course is to go with the flow (aller dans le sense du courant).
So...GEAUX SAINTS! And after we smash the Colts (écraser les Poulains), we'll all let "le bon temps" do its thing! WHO DAT, Y'ALL! (untranslatable)