Though not keeping the Dungeon-dwelling feeling of its predecessor, Diablo II still keeps you interested to explore.
The plains remain random generated, but this time, all the quests will appear normally, lessening its replay-value just a little.
The story, however, is way more intriguing and, this time, events take place as you venture through plains and dungeons, another difference to Diablo, as where you would be just hunting out cellars filled with demons from the aftermath of a drama.
In D2, the drama happens right before you arrive.
A feeling that you must haste, that your mission is urgent and needs to be done fast.
Now that the quests are inevetable, they are much deeper, requiring use of Quest-items more and fun twists. The Horadric Cube is a fun thing to fiddle with.
Diablo 2 is, just like its predecessor, a game you MUST have experienced, no matter your age.
Succumb to its universe.