This may sound like a shameless plug (though someone beat me to the punch), but unlike many other RPGs, FF6 has a lot of factors to equips that make "best" rather subjective, and it depends on what you want in a character, etc. As such, its probably best to just check my Character FAQ and see what they can use, and ideas around them.
If you want, just skip all the expositional banther that goes into GRUELLING DETAIL about a character's worth, and go to their respective equipment section; it might not be a bad idea to read up on the Equipment Set Up explanations so you can see what kind of set ups to use for what.
For example, briefly...
If you're taking Mog down the Dragoon route, he'll want to use the Holy Lance or Radiant Lance. If he's going down the Mage route, he'll want Gungnir, meanwhile. It gets more complicated with a few other characters, and this was just covering weapons, but I'm just portraying how there's not an objective "best" in some character cases (I mean, its hard to argue that Sabin wants ANYTHING over his REd Jacket...barring maybe Mirage Vest...****, even Sabin has a potential alternative option, if an obscure one, and that says everything...)
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