I'm a serious fan of Lamium (dead nettle) it's low growing, takes shade to almost full sun, and has nice silver and green foliage than goes nicely with many plants.

japanese painted ferns are another great choice, though a more expensive one (they take a while to fill in, or will cost you a bundle for the plants) but with the silver, burgundy, and green, they're really great shade plants.

and more of my sedums do well in half sun, so they will intermingle.

Hey Chinacat,

Thanks for the suggestion. I planted dead nettle last year, but my dog trappled it death and it did come back. This is not a space he'll be romping in, so I'll give it a try.

Don't forget Ajuga as well. It comes in several colorations and would contrast nicely with both sedums and lamium.

ps avoid lamiastrum, Yellow Archangel, unless you want it to be the Last Man Standing)