Answer: Which weapon is "best" really depends on what combat type you want to use. It also depends on whether you are a member or a non-member; members of course have more options available. Finally, most players will also want to consider the cost. Some of the weapons that have the best stats are terribly expensive. You may also have to consider your level.
If you have 75 attack and enough gold pieces, then you can get one of the many powerful Godswords of RuneScape. These are RuneScape's most powerful non-degradable weapons outside of Daemenoheim.
Godswords.
advice: get a weapon
A Weapon
There is no weapon stash in Runescape. If you need a sword or armor, you can either buy it at the Grand Exchange located at Varrok, or you can make your own.
There's weapon stores in almost every town around Runescape, look for a Sword, Bow, or battleaxe icon on your mini-map.
nothing
If you have a weapon in your inventory, click on it to wield it. This will un-wield any other weapon you have in your weapon slot.
Any weapon that has a great crush bonus:BattleaxesMacesMaulsWarhammers
all you need to do to get poison off of a weapon is use a cleaning cloth.
Gravite shortbow.
Dragon claws
There are many ways to get a weapon in runescape such as: killing monsters making them from smithing them or buying them from various stores.