I have the same spot. :o)

Mine is in transition because some plants got too large and I wanted a change. I have various hostas, bleeding hearts, primrose (NOT evening primrose!), centaurea montana, heuchera, trollius, columbine, coreopsis lanceolata, scarlet monarda, etc... I discovered a really nice astilbe a couple years ago, and have since moved in lots of them in different colors. There are many more possibilities!

Much of my backyard is shade, and some of it is dry shade (which is, I think, the hardest area to garden in). I use the following in my shade beds:
spring: pulmonaria, columbine, bleeding heart, trillium, siberian bugloss, forget-me-not, lily-of-the-valley, primrose, japanese primrose, solomon's seal, marsh marigold, rhododendron, azalea, sweet woodruff
summer: hosta, goatsbeard, astilbe, hydrangea, foamflower, coral bell, heucherella, lamium
fall: monkshood, toad lilies

I also mix in different plants that give texture like ferns. My japanese painted fern is a pretty mahogany color, and looks great with the other plants. The ostrich fern and christmas fern are just green, but they do fill in and provide texture.

In addition to what has already been mentioned, I have daylilies, sweet woodruff, gooseneck loosestrife, and spiderwort in my deep shade areas.

Tracy

Most of the above, plus aconitum, viola labradorica, tradescantia, narcissus, thalictrum, lobelia cardinalis, centranthus, alchemilla. Others that I can't think of without a trip through the gardens.

also astrantia, epimedium, doronicum, kerria (shrub) and PJM rhododendron

Erin -- try some foxglove. Big, bold leaves and yellow or pink flower spikes. Long bloom period, Zone 3 hardiness.

Astible plants would be perfect for this place and they come in red, pink, purple, white