Hi Will,
A few suggestions - you could do some research on species Hemerocallis, for example lilioasphodelus, or dumortieri which has a lovely scent to it. Or have a look at the leopard lily, Lilium pardalinum - from America not Asia - like the daylily but still a striking flower and a good perrenial lily. Iris is always useful depending on the position, foetidissima is the native - tough but with great flowers and seedheads. There are the siberian irises too and a whole host of others - unguicularis is great, early flowers and thrives in tough positions, but needs a good bit of sun. Hope they look alright to you? Alot depends on the aspect and the ground, then from there it's just plant browsing and choosing the best man (or woman) for the job.