Hosta is my no 10. Restful on the eyes among the froth of summer, big, bold and simple, and apart from slug protection - I just have to remember to start early, no attention is required, and clumps get steadily bigger and rarely need dividing.
No photos of the above yet - I'll take some this summer - but of course if you 'google' the name you'll get lots of images. I'm enjoying using only my own photographs in this blog - it's part of the fun.
With my ten star plants I think I can create a gorgeous garden with the minimum work: alchemilla mollis, hardy geraniums, foxgloves or delphiniums, nectaroscordum siculum, rosa glauca, hakonechloa albo-aurea, viola cornuta, knautia macedonica, japanese anemones and hostas. Underplant with lots of daffodils. Simple! Done!