Some examples of good German war gear:

StuG III/IV: they were one of the real triumphs of the war, a brilliant design that is largely overlooked today. They excelled as infantry support vehicles moving forward, or as tank destroyers in defense. They were cheap and easy to build (unlike the Tiger), they worked most of the time (unlike the Panther), they had a low profile and were easy to conceal (unlike both the Panther and Tiger), had good cross country mobility, and they could reliably knock out any tank in the ETO excepting the monster that was the IS series. We're all lucky (particularly the Red Army) that Germany didn't divert energies from building Panthers and Tigers and King Tigers and Mauses and so on into building as many of these as they could.

Type XXI U-boat. "Ahead of its time" gets applied to a lot of Wehrmacht stuff, usually incorrectly, but these boats were really a major step forward in submarine capability. Overnight, the Kriegsmarine went from having slow moving, easily detectable subs that were basically modernized WWI boats, to having a submarine with something close to modern capabilities...and in fact, some offspring of the Type XXI are still in frontline service here and there. We (meaning, allied merchant mariners) are lucky that Germany decided to build V2s and a couple of battleships and railroad guns instead of fast-tracking these things (and acoustic torpedoes) into the Atlantic.

The Me-262 hardly needs more written about it, but for the brief time it was in service there was no greater disparity between the best and the rest when it came to fighter aircraft in Europe. It wasn't just the jets, either...it handled wonderfully, had a ridiculous armament, had good visibility...its only problem was engine reliability, and slowing down to land. I'd hesitate to place it in the "superior" category conclusively as the US probably could have fast-tracked the P-80 to the ETO if it were needed (and man, that would have been a fight), but against the competition that was there, it was the best by a mile.

The StG 44 is also really widely known; no infantry small arm is going to be decisive as such, but it was probably the best weapon of its type to see widespread action during the era. Historical tip: the AK-47 had next to nothing to do with the '44, the only real influence taken from the German gun was the short ammunition.

German aero engines were consistently excellent. The DB601 was the best such engine in the world in 1940: excellent power to weight plus a real live fuel injection system...it was almost just enough better than the Merlin was in the summer and fall of 1940. The later variants on the same build, particularly the DB605, were similarly excellent engines but didn't have the same disparity in performance over their allied counterparts that the 601 did.

The Nebelwerfer werfed nebels about as well as anything. There wasn't much to WWII-era rocket artillery but the German 15cm rockets were excellent, and they used them to excellent effect. I'm not sure if I'd say it was better than the Soviet MRLs, but they're pretty much the same thing in most respects.

The Jerry Can was such a brilliantly simple design everyone copied the hell out of it, and still uses it. The idea of a fuel can having strategic implications seems laughable until you see what the British Army was dealing with.