It has probably already been said, but the easiest method that will reliably yield the best cooked steak is a slow, low temp bake finished with a hot cast iron sear.
There is a fallacy that starting with a sear will 'seal' in juices - many sources have tested weights of pre/post sear and shown little to no variation in weight from fluid.
Always let cuts of meat raise to room temperature before cooking. The slow bake method helps a lot because you can easily get the desired 'done-ness', let it rest, then finally add in the browning sear. If you start from the outside with high heat first your variation for internal cooking temperature will only be a handful of seconds; ie you will go from med rare, med, med well very, very quickly (also keep in mind it will continue to cook after being taken off of direct heat).
Sous vide is also very popular, but I don't feel like buying another machine for my already over packed kitchen.