Endless satisfaction. Excellent story. Best visuals in the genre by a long shot.
There's nothing else like Diablo II. If you enjoy a challenge and aren't afraid of a game that doesn't hold your hand with making the right or wrong choices, you'll fall in love. If you get frustrated by managing different sized items in your inventory, you might want to try the console version that auto-sorts it for you. Either way, the game will never let you go.