That's strange, I wrote a long reply and must have forgotten to send after I previewed it.
My garden is mostly full sun but I just now learned about B. Looking Glass Begonia or something similar. They grow fast and very easy to propagate and they last longer than coleus. You can find them cheaper at Lowe's, like some Rex Begonias. They are easy to root in water. And when it gets cold you can just cover them with a cardboard box or bring inside.
I also like Hawaiian Ti Plants, oyster plants and Snake Plants or Bird's Nest. I got most of mine in the clearance racks at Lowe's.