I'm a wee bit simple in this area. I would make a concoction of Coke, garlic and soy sauce and marinade it for while. Yum! I had BBQ about 15+ years ago with a Philipino friend's family. His dad used this simple little marinade and I have never forgotten it and do it myself now, too!
Korean Meat Marinade
3/4 cup natural brewed soy sauce
3/4 cup unsalted beef broth or water
1 small onion
1 small Nashi (Asian) pear or semi sweet apple
6 cloves garlic
1 inch fresh ginger
1/2 cup sugar, brown sugar, or honey
3 spring/green onion
2 teaspoons pure toasted sesame seed oil
1 tablespoon rice wine
1/2 teaspoon black pepper
Cut onion, pear/apple, and ginger into small pieces and place in blender with garlic and just enough water to blend into a smooth liquid.
Pour into medium mixing bowl.
Trim root and top 1/8 inch of green onion, rinse in cold water, and finely chop. Add to bowl.
Add all other ingredients. Mix well and let stand for at least fifteen minutes to let flavor develop.
Marinate meat for 1 to 24 hours.