Red Creeping Thyme
Fragrant foliage, too!
Just a few inches high, the plant is densely covered with tiny, dark green, shiny leaves that are intensely aromatic when crushed -- plant them between paving stones and enjoy their fragrance every time you pass by.
Evergreen in the South, semi-evergreen in the North. Plant 12 to 15 inches apart in full sun and well-drained soil. Zones 4-8.