The only no work option would be a wall. Even then you might sometimes have to do a little weeding.

Do you like mint?

Do you REALLY like mint?

I think you see where I'm going with this.

You need to determine what type of exposure the are gets before choosing what to plant. Whether it gets at least 6 hours of sunlight each day or is a shady spot will help you choose a ground cover that will be suitable for the site conditions and do well. You also need to consider drainage and watering but now is a good time of year (fall) to plant so the root system will be established by spring with the help of fall & winter rains.
Here's a really great article that discusses things to consider when planting on a slope~ Even though it's from a california nursery, much of the information is relevant.
http://www.laspilitas.com/garden/howto/slope.html

Here is a link that might be useful: Simple erosion control for a hillside or garden slope

Take a look at kinnickinick. I'm in Eastern WA, but I think this grows well in a lot of places. We planted 500 on our slope and you can imagine the weeding I did all spring and summer and into fall now. I'm now a slave to that slope but once it fills in it will be beautiful. They are very hard woody and low growing plant. We planted each one two and a half feet apart. They have grown nicely all summer but it will take until end of next summer to be mostly filled in. I think you'll like this plant. Once established, they don't need a whole lot of water. Better check on that as I'm just recollecting reading that.