Nice. Seaside is cute, but I agree with downtownPDX. It is family-oriented. If you make it up to Astoria, there are two great breweries - Ft. George and Buoy. Buoy is one of my favorite places to have a beer in the summer, where the Columbia meets the Pacific.
A bit further south, Canon Beach is gorgeous, as are points south, but the coast is rugged in places, punctuated by beaches. A good pit stop might be De Garde Brewing, outside of Tillamook, which does exclusively Belgian style sours.
My favorite little town on the central coast is Yachats. My fiance and I got engaged at Cape Perpetua, just south of there, this past July: