I'm going to assume this is a wine road trip since you're going to Paso Robles, so you'll definitely stop in Napa Valley. In Oregon, you could explore the Willamette Valley to try the best Pinot Noir and Pinot Gris. In Washington, go to the Columbia Valley AVA near the Columbia Plateau. Look for Cabernet Sauvignon, Riesling, Chardonnay, and Merlot. I would take at least 3-4 nights if you can, so you can do some wine tasting in every state.