The German Panzerkampfwagen V is considered to be the best designed tank during World War II, but the T34 is ranked as the number one tank to be built during the same time. It was easier to manufacture, massively produced and provided sloped armor for the crews. Now if I had the choice it would have to be the Panther Aus G.
Ernst Barkmann had some remarkable engagements in his Panther against Shermans. Barkman's Corner is a classic example of how superior tank crews could effectively use their vehicles to take on a much larger force.
Michael Wittman and the Battle of Villers Bocage is another example of a superior tank commander, a veteran of the Russian front, being in the right time at the right place to wreck havoc among a British armored column before they even knew what hit them. He was in late version Tiger 1 with steel roadwheels.