Aircraft.
Although I might tend to agree, some would find this debate-able.
Firearms.
Also highly debate-able and subjective as well. I like Ruger revolvers. And you could probably say that an AR-15 is the best 5.56 "assault" rifle. But pistols? High power "assault" rifles? Shotguns even? Hmmm. I don't know.
Here's some things that are more indisputable (but probably not 100% in all cases)
Operating Systems
Cinema
Soft Drinks
Bourbon (by default)
Guitars
Nothing comes even close to the f-22 and b-2 bombers.
Best firearms: 50cal,1911 .45, colt peacemaker,and Springfield 1901. Can throw in m1 in there.
(ok, that list is debatable, I agree, but the sheer number of really good firearms is amazing. All of the above are in production today, except maybe the M1)
Tanks.
Insinkarators!