My choice is an open fire.
Sure, there are times and places where open fires are not feasible, or even illegal. But when I started camping and hiking, more years back than I care to remember, there was no other way to cook. And 15 years as an historic reenactor solidified my view---open fires are the only way you are allowed to cook at those events.
That aside, the flavors imparted by woodsmoke are unequaled by any other method. So, when possible, that's the way I go.
They have taken the oath of the brother in blood, in leavened bread and salt. Rudyard Kipling