For hole-in-the-wall Greek, Golden Fleece (we only ever get gyros, so can't speak to other food). Complete with surly waiters, but not fancy.
We ate at New Parthenon post-auto show in January, we were a large group so ended up with family style--not impressed, other than with the excellent lamb chops. Everything else on the platters tasted the same, drenched in a unexceptional tomato sauce.
Golden Fleece Restaurant
525 Monroe St, Detroit, MI 48226
While not Greek I do like the Steaks at Monroe Street Steak House. Otherwise I have not been too happy with eating anywhere on Monroe in a long time. Well OK maybe getting something to go with Astoria is cool.
Pizza Papalis is just as bad as Fishbones.
Has anyone had a bite at Mosaic yet? http://www.mosaic-detroit.com/