The Diablo 2 Wiki
The Diablo 2 Wiki archive is available for anyone looking for information on Diablo 2. All information here is pre-D2R but contains a lot of useful information that is still relevant. Updated sections for new D2R features can be found on the PureDiablo Diablo 2 section

Category:Quests

Category page

Quests fill the acts in Diablo II, and must be completed (to some extent) to advance in the game. They offer interesting explorations and valuable rewards, and you can read all about them on the pages in this category.