We have been using this simple chicken marinade for years. It makes for some awesome grilled chicken. I like to use chicken thighs when we grill because they are so tender and juicy.
1 cup Sprite
1 cup soy sauce (I use low sodium)
1/2 cup oil (I use light tasting olive oil)
2 garlic cloves, minced (or garlic powder)
Put chicken in a big zip-loc bag. Pour in the marinade ingredients and seal up the bag really good. Move the bag around so the ingredients mix together and the chicken is all covered. Keep in fridge until ready to grill. Marinade at least a few hours or even overnight. If you don't have access to a grill, you can also broil them on a cookie sheet in the oven for about 12 minutes on each side.