I made this marinade for a piece of steak we planned on grilling. I left it to marinade for over a day, but you can get away with a few hours if necessary.
For this marinade you will need: 1/2 cup soy sauce, 1/2 cup olive oil, 2 tablespoons sesame oil, 2 tablespoons red wine vinegar, 5-6 garlic cloves (minced, grated or finely chopped), salt and pepper to taste.
Combine all ingredients in a ziploc bag with meat and seal without air. Refrigerate until needed and cook as you would like. We used a 2 pound piece of beef top round and grilled for about ten minutes a side. It was great that night, and even better as leftovers the next day. For lunch I sliced some up to top a salad and for dinner I reheated the slices with crushed garlic cloves slowly cooked in butter. I splashed some soy sauce on it to finish. Mmmmm!