The weapon of choice for the Crusaders was the broadsword.
guns were used
During the US Civil War one weapon was the most used one by the Union infantry. This was the 1861 Model of the Springfield rifle.
The cigar
the Apollo 18 was the most used weapon by the Koreans.
banking
A mangonel is a weapon that was used during the Middle Ages. It was used in warfare and the weapon is similar to a catapult.
Guns are the most common murder weapon in the United States. Handguns of 22 caliber and 38 caliber are most used.
Nuclear weapons were not used during the Vietnam war
They Crusaders which participated in tournaments had a sword spears a shield a horse and sometimes a weapon of their choice and sometimes knives
There are two types of crusades: the political crusades and the religious crusades. The crusades are used to win new converts and inform. Political crusades are usually used for power and fame.
Gas was often used during WW 1 and probably caused the most damage.
A 303 rifle : The above is one answer. However, if one defines weapon as "that which is used to kill people", then the gas used at the concentration camps, principally Zyklon-B, was the most used weapon.