Are you looking just for autumn bedding, or something that you'll leave there all year?
If the latter, try heathers (though they like acidic, damper conditions), ornamental cabbage, viola's, cyclamen (though most types from garden centres are not hardy - i'e won't stand frost). Gaulthera has good berries.
If you're after year-long ground cover, then vinca (periwinkle) is nice - evergreen, nice flowers, can get variegated forms, or cornus Canadensis (white "flowers" in spring, red autumn berries) Maybe intersperse with winter-colour, eg small shrubs of eonymous (evergreen, variegated), skimmia (pyramids of red or white flower buds all winter, evergreen), sarcoccus (scented winter flowers, evergreen). they'd last year-t0-year.