Rib Eye. USDA Prime,or Certified Angus if I can get it, from the local butcher. Prefer no marinade. Just some Olive oil,salt about an hour or two before grilling to keep in the juices. Left out to room temperature,then pepper right before going on the grill to give it that tasty crust. Reverse seared by Grilling over indirect heat lid closed to about 120 degrees and seared over direct high heat.lid open,flipping often for a couple of minutes to 130. Let rest for 5 minutes or so to get to 135. Tastes so good no sauce is necessary. Though I still like Heinz 57 on the side for some reason.
Invest in a meat thermometer. If you're going to grill a steak,get it right!
Sometimes I marinade in soy sauce,worchestershire and Cavenders greek seasoning for a different yet also tasty steak.