That festival is such a hoot-- no pretentiousness, just happy campers! That said, be careful on the 101 and stay to the outside lane when possible.
When I was a local, the wineries that I found myself at again and again were:
Amity (gorgeous view, lovely wine)
Winter's Hill (wonderful, wonderful pinot)
Helvetia (closest winery to downtown Portland, probably. His whole cluster pressed chardonnays can be just wonderful, and some of his pinot gris vintages are the sunniest decoctions of grapefruit or granny smith. Yum.)
Lange (a little stuffy but wonderful wine made by serious people)
Domaine Drouhin (my favorite chard, and divine Burgundy style pinots)
The brewpub in Pacific City (I forget the name, but it's the only one in a tiny town, right on the beach) makes fantastic beer. It's a wonderful place to get the sampler and then watch the ocean. The hike up the hill just to the north of it is well worth the view. Raccoon Lodge has wonderful beer. If you want a really scenic detour, Walking Man is east of Portland and can have some terrific offerings. If you go that far, be sure to visit the Cascade Cliffs winery.