So I can imagine getting some disagreement when I say that Flower Carpet roses are hands-down the easiest roses to grow. By all means, leave me a comment if you have a rose you'd like to nominate instead! But, I'll take some convincing....
Flower Carpet roses have been around for almost 15 years now and are unique from the other major rose categories (ie. floribunda or hybrid tea) because they produce new growth from their roots. A rose that doesn't have to stand as ugly bare canes in the winter- whoever thought of it is a genius! You can literally runs these things down with your lawnmower and they will grow back even more beautifully. They are covered in blossoms throughout the spring and summer, especially the red, pink (apple blossom) and white. The orange (amber) and yellow are a little less vigorous and have a taller, less compact shape where the flowers are mostly born on stalks that stand out a bit above the foliage.
I always find myself wishing for more plants in the 18"-24" height range and these fit that niche perfectly. As you can see from the photos, they look great in mass plantings.
There are a lot of knock-offs now, like "Floral Carpet", and I have less experience with those, although I expect that they are fine and may even be grown from the same stock. I tend to stick with the Monrovia trademarked Flower Carpet, since then I know they will be top quality.