Picking up an off-topic thread from the Bay Area board ...
Is there any great riesling in California? Even any good dry riesling?
Anderson Valley (Mendocino) makes some excellent gewurtztraminer (Lazy Creek, Navarro, Handley, Husch), but I've never been very impressed with the riesling, with the exception of some Navarro late-harvests.
Thomas Fogarty makes good gewurtztraminer from Ventana / Monterey grapes but no riesling.
Bonny Doon makes some decent but not great riesling, not sure where they get their grapes.
There's some riesling in Santa Barbara but I haven't had it.
The Napa and Sonoma wine regions don't have a good climate for German / Alsatian varietals.