Not always a fan of FLW in general, but I DO love his design for the Marin Civic Center. Google pics of the interior, it's full of light and very warm and friendly for a government building.
Also like the creepy-ass house on Franklin Blvd in Hollywood which his son Lloyd designed--the one connected with the whole Black Dahlia/Steve Hodel story. I like the so-called "John Sowden House" better than many of Wright Sr.'s buildings. It has a very brooding, ominous quality. 1940: