The West Coast definitely dominates the surviving movie palace landscape, thanks to Hollywood's legacy as the movie capital of the world.
As much as arthouse culture might seem like it would be an East Coast staple, it's been hard for old school theaters to survive in such busy, ever-changing cities. These old school theaters are true survivors!
The Midwest actually has a really robust old school theater scene: the Chicago area (in particular) has taken great care to preserve its architectural links to old movie production and culture (and its old theaters / movie halls!).
There's no shortage of beautiful old movie palaces in the South: my childhood favorite, the Inwood Theatre in Dallas, actually inspired a lifelong love of old school movie theaters!