What is the fastest way to make zeny? What is the best class to make zeny?

What is the fastest way to make zeny?
Diabolo's Gears are very expensive and some characters can solo them (Lord Knight can get Diabolo's Ring[1])
Champions can get Diabolo Robes and Cross Shields, they are the very strongest classes of breaking those monsters alone. Gets better with a help of lex and prof, asura spam... and devotion paladin to sacrifice himself for his comrads.

What is the best class to make zeny?
Snipers can hunt general monsters and make more money depending how fast he kills them!
Paladins can throw their shields linked and kill the kiel dung map entirely before link goes off!
Assassin Cross can grimtooth anolians and other high profitable monsters easily!
Assassin Cross can 1 hit Bio3 monsters!
Sin-x/Whitesmith with icepick can 1 hit geffenia monsters!

Thats it for now, good luck.