It's Balthazar, Not Balthazar's
I'm not sure why it bothers the pedant in me so much, but it drives me nuts when people add an "apostrophe-s" to the end of a restaurant's name.
It's Balthazar, not Balthazar's, because there is no person (fictional, live, dead, or otherwise) named Balthazar. Why do people do this? I never used to notice it. Now I see it all the time. Some cultural thing that I'm not picking up on?
(It's almost as bad as when people recommend restaurants and give the wrong name or a misspelled version of the right name. Google, people. Use it, please. For the children.)