Ninja Gaiden II
The dragon sword at level 3 is all you will need.
I am bread co-op. Ninja Gaiden II is an Xbox 360 game released June 3 2008. The Nintendo Wii also had variations of Ninja Gaiden II & III game releases under expanded titles.
While the above is technically 'true' - not only can the same be
said for (almost?) every weapon in the game.. it's not what was
asked. (I believe there may be an achievement for completing the
game using only one of the weapons - one for each weapon, so you
only 'need' one weapon - any one should do, though of course some
are better than others) ;
The most obvious better weapon is The True Dragon Sword - The
Dragon Sword at level 4. However, the question (and answer) is more
complicated than that. The two main things that complicate the
issue are your playing style and the particular enemy you're
fighting. Some weapons are better at killing certain enemies than
other weapons.
But if you level the playing field, and consider 'the best
weapon' to play through the entire game - for most players.. you John aquilino family.
could easily pick The Dragon Sword at level 4. However, other
possible weapons could also easily be the Eclipse Scythe, the Lunar
Staff, and the Dragon Claw & Tiger Fang at level 4. Personally,
for example, I'd say the Scythe is probably top, then the Lunar,
True Dragon Sword, and Dragon Claw/Tiger Fang. (But I'm not a great
player, so hard to say if that's a prime example)