"Top 10" of medicinal herbs grown Midatlantic region?

I am an avid gardener, and am very familiar with growing vegetables, fruits, and culinary herbs. I have recently become interested in the medicinal uses of herbs, and would like some ideas on what to plant in my garden, which is in Chester County, PA, just outside of Philadelphia. Space is not an issue, nor are locations dependent on partial shade, full sun, &c. (we have several gardens around the property which afford just about any combination of sun and shade, drainage, &c.).

So my question is, as I am just getting started with medicinal herbs and do not want to devote an *inordinate* amout of space or resources to them (i.e., I don't want to start with a giant garden of 50 different medicinal herbs), what might be a good "Top 10" (or Top 5 or 15, 8 or 12, whatever) of multi-use medicinal herbs. The ones most common in many preparations.

Please discount culinary herbs, which I already grow: basil, dill, oregano, marjoram, chives, parsley, rosemary, thyme.

Thanks for helping

Lemon Balm
Goldenseal
Ginseng
Echinacea
St. John's Wort
Stinging Nettle
Dandelion
Feverfew
Milk Thistle
Burdock
Valerian