Best Farming Place for DF

The Pumpkin Patch.
It is accessible through either Lugosi (Amityvale Weapon Shop Clerk) or just walk East 2 frames. On average (for level 15-20ish) it coughs up about 2000 exp (if all of the monsters are defeated) and around 500 gold. The quest reward is 1 Moonglow. Moonglow are used in the production of powerful light weapons.

These weapons are called Moonstriker, Moonbleed, and Mooncrash. They are level 15.
The stronger ones are Exalted Moonstriker, Exalted Moonbleed, and Exalted Mooncrash. These weapons are for level 22. Aside from Mighty Purebeam (rare) they are the strongest light weapons in the game.