I like mine pretty spicy, so this may be a little bit much for some people:
1/2 cup worcheshire
3/4 cup soy sauce
1 cup water
2 teaspoons liquid smoke
4 teaspoons black pepper
4 teaspoons cayenne pepper
4 teaspoons salt
4 teaspoons onion powder
4 teaspoons garlic powder
This is enough for about 10 pounds of 1/4" thick jerky strips. Marinate overnight in the refrigerator in a tightly covered plastic or stainless container (it will really stink up a refrigerator!) at least overnight. "Squeege" off the strips between your fingers before putting them on your dehydrator racks and dry them until leathery (6-9 hours, depending on your dehydrator). I put the strips in ziploc freezer bags, squeeze out the air and store them in the freezer, and they stay good for at least 6 months (you could also use your vacuum foodsaver).
You could cut back on the cayenne and black pepper if you don't want it quite so spicy.