Where are good places to farm souls in Dark Souls?

Two areas that come to mind for quick soul farming are the forest hunter's area in the Darkroot Garden and the Painted World of Ariamis.

Darkroot Garden - Purchase the Crest of Artorias from the blacksmith in the Undead Parish for 20,000 souls (this initial investment can quickly be earned back). Next, go down to the forest from the undead parish and head toward the giant stone doors. Use the crest to unlock the doors. In the next area are several NPCs each worth 1000 - 3000 souls. There is a bonfire hidden behind an illusion wall in the ruined structure just before the crest door. The 2 knights in heavy armor and the archer will not respawn but it is still worth it to farm the sorcerer, cleric, thief and bandit. To use this method you must not be in the forest hunter's covenant.

Painted World - Requires a bit more effort to get to but is a bit more efficient if I recall correctly. First you must return to the undead asylum by climbing to the crow's nest in Firelink. In the asylum return to the cell you started the game in and retrieve the Peculiar Doll item. Next, go to the room with the giant painting and white robed enemies in Anor Londo. If you interact with the painting while you have the doll you will get transported to a new area. The new area contains the phalanx enemies (deformed enemies with spear and shield) that are easy to farm once the shortcut to the bonfire has been opened up. Once finished farming the only way to leave the area is by heading to the arena where Priscilla is and jumping off the ledge.

I take it that you're building an Int build then.

I myself have a dex build and have been farming in anor londo myself a lot by parrying silver knights. After a few tries you get their patterns down and they yield a lot of souls. Because of the crit damage from the parry/riposte you get 20% extra souls.

• Silver Knight (spear/sword) : 1000 souls
• Silver Knight (dragonslayer bow) : 1300 souls
• Silver Knight (spear/sword) Crit : 1200 souls
• Silver Knight (dragonslayer bow) Crit : 1560 souls

I am not sure how well an int build can exploit this, but they are my primary source of souls.

Since you're in Anor Londo, you can go to the first bonfire and farm the sentinels. They go down fast with a bleeding weapon. This area is also not open to invasion if I remember correctly.

In addition to Monkeez answer, Painted World was my favourite place to farm. Using Poison Mist (bought from Engyei in Queelag's Domain) you can poison most of the Phalanx in one hit. Then, while they're dying, you can either run down toward Priscilla (kill everyone on the bridge) or clear out the Annex. By that time the poison will have killed most of the Phalanx enemies, leaving only a few to pick off.

So roughly looking at ~30,000 souls in 5-7 minutes.

Repeat as necessary!

The baby skeleton just before nito drop humanity and they always come back. Goldserpent ring and silver help a lot when you tire go feed the humanity to the Kingseeker Framp at fire link shrine .