It varies on the meat, the cut, the style, the weather and what I feel like.
I regularly use: cast iron, a propane grill, a santa maria grill with cut up wine barrels (they burn really hot and really quick, not good for much else), a searzall or a blowtorch.
I've also used a blazing charcoal chimney lowered over the meat, a wood fired pizza oven at 900F (-ish), an el cheapo grill with briquettes or lump mesquite, a weed burner, an electric cuban sandwich press at full tilt, a ginormous 4-burner propane griddle (end result was the same as cast iron, just bigger).
The one thing, ok, two, I haven't done yet is a rosebud on one of my oxy-acetylene torches, and LM2500 exhaust wash.
Probably a few
Don't skimp and don't fall for marketing BS by the celeb chefs pimping their own Chinese made sub-par lines. Buy US made Lodge brand, you won't regret it.