What is the highest possible attack rating in Dark Souls?

What's the highest possible attack rating for a melee weapon in dark souls?

Assuming max stats and using any enchantment on any weapon. Right now I am getting 706 rating with the crystal demon's greataxe +5.

Solution 1:

The Demon's Greataxe has the highest potential raw damage, due to nice base attack rating and S-scaling in Strength. A Crystal Demon's Greataxe +5 wielded with 99 Strength has 767 attack rating.
^{Note : Two-handing doesn't boost damage at 99 Strength}

This weapon can be enchanted.

The best weapon augmentation is Darkmoon Blade ; when rank 3 in the Blade of the Darkmoon covenant, (magic) damage increase is 2.1x of the magic adjust of the equipped talisman.

The best talisman is the Darkmoon Talisman. With 99 Faith, it has 240 magic adjust, resulting in 504 magic damage for Darkmoon Blade.

Maximum attack rating in Dark Souls : 1271, with 99 Strength and Faith, Crystal Demon's Greataxe +5, Darkmoon Talisman, and Darkmoon Blade.

Starting with the Cleric class, this is SL174, long but not that hard to achieve. No ring nor equipment piece can boost this rating.

Here is the build on Mugenmonkey.

Praise the Sun !