Many people think that katana is the best sword, bringing up arcanes of sword-smithing and it's legendary power as a proof. The truth is, however, that katana is definetly overrated. We can see many runner-ups, which are equal or better in different conditions than katana, such as polish hussar sabre, french napoleonic sabre, persian and damacus scimitars, or chinese
miao-dao swords or other
daos.
Why is it so overrated then? Particulary, because Saumrai and other ninja-stuff is just
cool. Katana, Ninjas and saumaris became part of pop-culture, and for average people who don't have much knowledge about swords, it's even more cool. When there were so many films about ninjas chopping and owning everyone with their katanas, it's easy to think that way.
The other argument is that samurais fought rather against other samurais, because Nippon was pretty isolated and politicaly divided. There's hardly any comparison to other swords, when you fight with katana against katana. Even Myamoto Musashi, the best swordsman amongst samurai, preffered large, solid stick!

During times of samurais invasion Korea failed (if samurais were so cool, why won't them succeed against Koreans?). and later, in First Sino-Japanese War Japs preffered european sabres or bayonettes.
Finest blacksmithing? Geez, don't make me laugh... Is the damascene steel worse? Or Napoleonic/Early Modern steel is worse?
Such proofs as guys with katana choping bamboo sticks doesn't make any proof, because you could do same thing with ANY medieval/reinessance/early modern/ napoleonic sword.