I'm also in the NW, one of my borders is heavy clay and poor draining. It's wide, so some of what I've got is probably bigger than what you're after but the shrubs include:
Dogwoods, hydrangeas, rhododendrons (the soil is neutral not acid, but we treat their area with iron sulfate which keeps them happy), mahonia, euonymus, spirea.
Perennials include astilbe, geraniums, purple loostrife, phlox, a couple of different types of campanula (tall lactiflora and the ground cover sort), candelabra primulas,iris (the bog garden type) , pulmonaria, crocosmia, aconite, vinca, ajuga reptans. (Theres a few other things I can't remember the name of).
On the fence theres ivy (we didn't plant it, and it's hard to control), pyracantha, a jasmine, some clematis including a clematis Montana.
And there's also random self-seeded foxgloves,honesty and forget-me-nots. And too much red campion.