What about the Colt M1911, and the Thompson sub-machine gun - both of which were considered prize war trophies and much feared by the Germans? The Willis Jeep was considered the best all-round utility vehicle of the war. In the ari you can add the B-17, the P-47, the P-38 and even the B-25 and 26.
American armor, while initially out-gunned and out-classed in terms of armor protection was far more mechanically reliable, more manueverable and faster than German heavy tanks. Most knocked-out american tanks were returned to service within days, often more than once, while a knocked out German tank tended to stay that way. Once fitted with high-velocity 76mm and 90mm cannon and improved armor protection, American tanks were much better able to take on German Armor if they worked in teams. The biggest problem with American tanks was actually their gasoline engines, which, though reliable and producing more power to weight than a diesel, burned readily when hit.
The only area in which American equipment was inferior to German equipment was in tank technology. In almost every other area, our equipment compared favorably or proved superior to German arms - with a few notable exception that are always pointed to as proving the rule.
German intelligence critiques of most American equipment during the war were quite favorable. Nothing scared the German infantryman more than the sound of a Thompson or an M2 nearby, and they tried whenever possible to get hold of Colt .45 pistols because of their reliability and stopping power.
One of the comparisons that is always made is between the Bazooka and Panzerfaust. The Panzerfaust packed a real wollop, but had only half the range of a bazooka and presented the problem of Ammo supply because they were single shot and rather bulky if you tried to cary more than one. A bazooka team, however, carried a reusable launcher and could carry more bazooka rounds. While the bazooka was not effective against most german tanks, it proved quite the bunker-buster and proved to be such a useful infantry weapon that the Germans copied it late in the war with the introduction of the Panzerschreck.
There was also the critical factor of transport across the Atlantic (or Pacific). Marshall rejected heavy tank designs because he could get many more Sherman-based vehicles on a cargo/Liberty ship than heavier designs. Also, a singular chassis/motor set, as in the Sherman, also simplified maintenance and logistics to a great degree.
Not to mention the Mustang and the entire Cat series. Even the P-40, with the right tactics, put a butt-whoopin' on the Japanese in Indochina. It was slow, lacked armament, couldn't dogfight, but it could absorb punishment, had a higher ceiling and much faster and more stable in a dive. Chennault was brilliant enough to use its strengths. His squadrons flew as high as possible and dove out of the sun on Japanese squadrons, pulled up and went to altitude again. They stayed away from macho dogfights, and did what it took to win, against all odds. It amazes me to think about it.