Good marbled thick ribeyes (not marinated). Rub some Extra Virgin Olive Oil on them. Let sit at room temp. for about 20 min while you heat the grill or cast iron on gas burner. My gas grill has a thermometer on it and I let it get as hot as it will go (says 600 deg., but I'm not sure it's accurate. Throw some kosher salt and fresh ground pepper on the steaks. Be generous with the kosher salt - a lot will fall off anyway. Stand back and throw the steaks on - the first side should sear in about 20 secs if it's hot enough, it should sound kind of like a jet taking off when you throw them on (notice I said "throw" this is highly recommended if you intend to keep your eyebrows. Flip steaks, then turn gas as low as it will go and close lid or cover skillet. Cook for about 2-3 minutes for rare, 7-8 for well.
-Never poke holes in the steak - turn with tongs.
-After you take off grill let them sit at room temp for a couple minutes so the juices re-distribute back through the meat.
-Don't put the salt on too early, just before cooking.
-Always cook on cast iron grates (never covered with aluminum foil) or in a nice seasoned cast iron skillet.
-Use the "Palm of Hand" technique to determine doneness - never cut into the steak to see how done it is.
The only real secret to cooking steak is the extremely high heat at the very beginning so it seals in the juice...the juice keeps it tender. It also creates a BUNCH of smoke at first - this is why I consider it an outside only job.