What's the BEST/your favorite marinade for steak & chicken?

For Christmas, my family sent me a box of Ohama Steaks – chicken, burgers, dogs, steaks, potatoes – but I just started eating meat a few months ago. There’s this amazing place in NY that bottles their marinade, but I don’t have that here. What are your favorite ways to flavor a steak, chicken, burgers? I prefer homemade recipes, but I am open to using a store bought products too!