Diablo II is a hack-and-slash adventure and fighting game. It's very fun to play, and there are so many things to choose from in the game that it's never boring. You can choose from five characters: Sorceress, Amazon, Necromancer, Barbarian, and Paladin. My favorites are the Paladin and the Necromancer. The Paladin is a melee fighter with auras that can strengthen your allies. The Necromancer is able to summon skeletons, the dead, and other creatures to fight other evil beings. It's pretty cool just playing these characters and having them level up and get stronger items.
There are several chapters, and for each chapter there are several missions. The last missions are usually the ones where you have to face and defeat one of the great evils such as Andariel, Duriel, and two of the Three Great Evils Mephisto and Diablo. Accomplishing the quests are really fun and challenging. It's exciting to face really strong enemies.
I highly recommend Diablo II. Buy this!