Siege on Harrogath

Best quest ever. You get to farm Shenk, stop the siege, grab the FH WP, farm Eldritch, and get a socket option. Win, Win, Win, Win.

The " Larzuk Quest", which low-level burner characters can easily be rushed to to add sockets to equipment.

A single socket will be added to unique, set, crafted and rare items.

A magic item has a 50% chance for a single socket and a 50% chance for two sockets (unless the individual item type cannot have two sockets).

Low, Normal, and Superior quality items will have the maximum number of possible sockets added, which is dependent on the item's ilvl, item category (i.e. helm, pelt, club, mace, etc.), and the maximum number of sockets for the individual item type. Recipe: Normal Quality Armor of Same Type and Recipe: Normal Quality Weapon of Same Type can be useful for obtaining a specific desired number of sockets on an Exceptional or Elite item. A more detailed breakdown can be found here.

During theorycrafting, it is generally assumed that any best-in-slot, non-runeword helms, armor, weapons, and/or shields will have this quest reward applied to them.