Having recently had a couple of Navarro Late Harvests with a decade or more of age, Navarro has to be near the top of the list. On a par in quality with very good German Ausleses and Beerenauslesen.
Dr Konstatin Frank was the first that came to mind for me. Although I’m out of touch with the current state of Funger Lakes Riesling so there may be some up and comers. There’s also a lot of promise out of Michigan, and since you didn’t say US, Niagara also has several top notch Riesling.
I should clarify. Morten Hallgren from Ravines is coming to CO to lead the third “Cultivar Camp” on Riesling. We have identified a selection of Alsatian, Austrian, Australian, Finger Lakesian and German Riesling to pour but are looking for the finest example of U.S. West Coast (preferably on the dry side of the spectrum) Riesling. We’ve been thinking Eroica, Navarro, and Smith-Madrone. I was just looking for some other suggestions that we may be overlooking.
From a PNW perspective (I know nothing of CA, NY or MI Riesling) - skip Eroica and Poet’s Leap if you are looking for dryer wines. Try Paetra, Love & Squalor, Ovum, Brooks, and Savage Grace.
If you want WA representation besides Savage Grace, seek out Rieslings from Evergreen Vineyard and Underwood Mountain, although I’m not sure who produces in a dry style from these site (Efeste perhaps?).
If you are looking specifically on the dry end of things Brooks makes some trocken style wines that I don’t care for but are certainly well made. I really like their off dry Bois Jolie. Or you could do a lot worse than the Eminence Farms riesling.
I was going to say Ravines or Hermann J Wiemer. In all honesty I think the FLX far outstrips what I’ve had from the West Coast, but the best West Coast rieslings I had were from Oregon. Brooks had some I was impressed with.