There are lots to consider if you go to the bottom of the page, click on G and then click on ground cover plants.
Depending on conditions and the amount you wish to cover? some of my favs include Phlox subulata 'Emerald Cushion, Aubrieta Dr Mules Variegata, Dryas octopetala, and Nepeta 'six hills giant'. For large areas look at the Hypericums and shrubs such as Cotoneaster horizontalis and Juniper 'Green or Blue carpet'

Helianthemums are good in sun - check the height, some get 6 inches, some up to a foot high. Otherwise, Campanula portenschlagiana, Iberis sempervirens, Oreganum aureum, Hebe youngii.

I'm trying Delosperma. it has succulent type leaves and seems really quite vigorous. They come in a variety of colours but the flowers only seem to come out when the sun is out. Very pretty though and I would recommend it as its really easy to grow !

Sedum spathulifolium, Cotoneaster congesta, Azorella trifucata, prostrate juniper for a few more. There is a New Zealand plant that is covered with bright red burrs at this time but I just can't remember what it is called.

I think Bulba is thinking of acaena?

Thank you, Andrew, that is just what I was thinking about.