Hard to say
samurai swords/katanas are cutting swords that won't do much to plate armour whereas a knight's sword is a mix of a cutting weapon and a clubbing weapon, but the samurai would be more agile (not that a knight and a samurai would have ever fought each other, obviously)

There's no perfect sword; someone with a pair of nepalese fighting knives (kurkris) will easily defeat someone with a longsword if they're an expert.
( custard, Sat 13 Jun 2009, 18:59, archived)

you aren't meant to reply seriously to that question :/

( well, Sat 13 Jun 2009, 19:00, archived)

twas a interesting answer though
and it no doubt will be one of the summer movies of next year.

Knights vs Samurai

Directed by Will Smith.
( Tyronne Get To Falkirk, Sat 13 Jun 2009, 19:17, archived)