I find Campanula very good and attractive. Campanula Portenschlagiana work really well in the UK.

I use macrorrhizum geraniums a lot but if you scroll down to the bottom of the page and click on G and then Ground Cover there are pictures of lots more ideas.

Ground cover plants can be used for poor or rich soil, shady, part shade or full sun, wet or dry depending on which plants you choose. The list is endless and here are a few of the ones I use as ground cover in my garden. Sedum ellacombianum, Phlox subulatas such as Emerald blue and Candy stripe, Aubriaeta Red and Blue cascade,
Campanula poscharskyana (Serbian bellflower), Cerastium Snow in summer, Dianthus deltoides flashing light, Dryas octopetala, Geranium war grave pink, Nepeta 'six hills giant' Phalaris arundinaera, British lavender and Horizontal Junipers.

Thymes, dwarf dianthus.