Games : Diablo 2 Mods that expand story

I love the game Diablo 2. I've been a fan of the series since I first played Diablo 1 when I was around eight years old. I sort of put the game to the back of my mind for a while, but recently pulled it out to once again save Sanctuary. However, recently I'm finding that I can only take so much of beating the game with a new character, then beating it again on Nightmare, then again on Hell, and then grinding until I've reached max level, etc, etc. What my question is, are there any good mods that add to the Diablo II storyline, or even possibly start an unrelated storyline? Now, I've tried out Median XL and games like it, but what I'm really looking for is something that introduces new areas, new quests, and more story, without changing the classes and game mechanics I've come to love.