Gardenia radicans is one and also consider Sarcococca hookeriana var. humilis (Sweet box).

I have good luck with Gardenia 'Frostproof'. It's about 3 ft x 3 ft, evergreen and has fragrant blooms in summer.

Thank you both for your replies. Gardenia seems to be winning out. Are they an easy plant to maintain? Meaning do they new a lot of trimming/pruning to look good. One of the reasons I'm replacing the boxwoods that were there is because it took a lot of trimming to maintain their size.

Gardenia is naturally a rather loose looking shrub. The G. radicans forms and cultivars naturally stay smaller - I only prune the occasional stray branch that might get bigger than the others. I would say that I don't even have to prune every year with these, just as needed.

I've had my 'Frostproof' gardenia for 3 years and never pruned it. It has a nice natural shape. I had a problem with whiteflies this spring, but one treatment with a systemic insecticide took care of the whiteflies completely.

I have the small gardenias in my yard. I'm not sure what cultivar they are, but they were called Mini-gardenias or creeping gardenia. They are very low (about 1 foot high) evergreen and produce a lot of flowers. The only issue I had with them was when they almost died with the Easter freeze in 2007. But they've come back strong. I was thinking of getting a few more. I've never had to prune them, which makes them a lot less work than the mini-boxwoods that always have to be clipped back.

Just to clarify, both 'Frost proof' and 'Radicans' are considered cultivars of Gardenia jasminoides. And I'm sure there are others.

Here is a link that might be useful: Gardenia jasminoides 'Radicans'