I was looking to marinade some veggies, and I found 
this recipe and adapted it a bit for my tastes.
Here's my version that filled my house with an incredible smell.  I'm sure this would be good with chicken, too!
Here's my variation:
 1/4 cup soy sauce
 2 tbsp. brown sugar
1 tsp. ground ginger
 1/4 cup vegetable oil
 2 tsp Worcestershire sauce
 1 tbsp rice wine vinegar
 1/2 tsp. garlic powder
 1 1/2tsp. dry mustard seeds
 pepper to taste
The pepper really was important, it wasn't mentioned in the first recipe, but it was so good.  Worth adding.  Enjoy!!