Ah, the good old 'Germans were the best!!!!!!111111' argument still lives. I thought I escaped it when I left high school, but, whatever. It makes me feel nostalgic.
Anyway, the Germans did have their superiorities over the Allied powers. Certainly, the Tiger and Panther were better than the Sherman tanks qualitatively, though the Sherman was a vastly better choice from a quantitative perspective. The T-34, on the other hand, was probably the best machine from a quantitative and qualitative perspective of the entire war. Though the Allies would never field an assault rifle, the Germans never managed to equip more than a small fraction of their army with the weapon, forcing most soldier to fight with bolt-action rifles. Their American counterparts, on the other hand, fought with Garand semi-automatic rifles. This is of course a general trend in Germany's economy: they could design good weapons but could not produce them. It was not only that the United States had more industry than the Third Reich, it had better industry. The average American worker was twice as efficient as his German counterpart in both agriculture and industry. German industry was far too connected to its craftsmen origins and did not fully embrace mass production. During the war, the United States increased its lead in efficiency as it strictly limited the number of different models of various war goods while Germany produced a multitude of different weapons that performed the same function.
In regards to air forces, though the Me-262 was the first operational jet interceptor, the British hold the record for the first operation jet fighter, the Meteor. German jets would be plagued by poor engines and insufficient thrust. The Americans and the British would lead the Germans in heavy bomber technology and, naturally, carrier aircraft. The best tactical air force is usually granted to the Red Air Force, the the USAAF leading as the superior strategic air force.
In the harder technologies, the Western Allies seemed to hold the lead in radar technology, though the Battle of the Atlantic makes for an interesting study in the race between detection and counter-detection technology. The US of course holds the ultimate trumpt card in the atomic bomb, something the Germans never came close to completing. The Germans certainly held an advantage in strategic rockets, though I would argue their impact on the war was negligable in comparison to the tactical rockets of the bazooka, panzerfaust, kayutsa, and Nebelwefer.
If we really must get into the argument of who was the best the soldier, I believe we are in agreement that the Soviet soldier fought harder than any other combatant in the war. The American soldier largely proved unaggressive though it should be remembered that unlike the German/British/Soviet soldier, his homeland was not directly threatened by the war in Europe and the infantry received the least capable soldiers in the army. When capable, motivated soldiers were placed in the infantry (Rangers, Airborne, Marines) they were the match of the infantry of other combatants. As Max Hastings in Armageddon states, the US was not a militaristic society but rather an industrial society. It not surprising then that the biggest advantages of the US rested in the industrial sector.