Here in Guam they use a marinade that is quite simple and yet very good:
4 cups soysauce
2 cups FRESH lemon juice (Vinigar can be substituted and often is, but not as good in the end)
1 chopped onion
2-3 cloves of Garlic
3-4 slices fresh ginger root chopped
Black pepper to taste
Soak meat usually at least 8 hours ( Chicken, beef or prok are all used in this)
You can vary this recipie with the use of pineapple or other fruits like Papaya ect. I add 1/2cu brown sugar to mine. If you add the pineapple or papaya be careful and not soak for more then a couple hours as these fruits break down the meat tissue. Sesame seed oil is a nice addition, it gives a somewhat nutty taste to the marinade.
Now they also make a condiment called fennadene it's really good to dip your meat into after grilling or to top your rice (here in Guam you can't have a BBQ without red rice)
1/2 cu soysauce
1/8 cu FRESH lemon juice
1/2 small onion (more or less if you wish)
Black pepper to taste
1-20 (Chuckle chuckle) fresh hot peppers crushed (to taste actually)
Seedy