Diablo II: LOD, I used to be a little skeptic about playing Diablo, until i tried it, Skeptic no more.
Music, i don't know why, but i like it, like all the soundtrack although at some point it does becomes repetitive (after like 2-5 hours of grinding mobs), still you'll be so Focused in reaching that next level, trying to get that armor part you've wanted for some time now, or trying to finish once and for all those pesky Prime Evils, that you won't even bother about the music amd you'll just enjoy it.
Difficulty, the difficulty it's something like custom, you begin in normal difficulty and it's up to some point somewhat easy, or that's what you think until you see the act bosses, then you start to see real difficulty, and why i say is custom? that's because it depends on the class you pick, the building of your character, for example, A magic wielder won't be as resilent as an melee character, still with the right build it can still kick the same kinds of ass.
So it's up to you whether it's easy or difficult.
Game content, up till now i keep on discovering things, every time i step out to the wilderness i find something different, ranging from different mobs which didn't used to be there before to different kinds of loot, so there are a lots of thing to find, and even after finishing my first play trough, i still don't think i have seen all, specially because after your first play trough, you can play again but in a different difficult (finishing the game is a requisite to unlock harder settings anyway) and in the harder settings, apart from the usual harder enemies, you get different things that on normal you won't, some areas become bigger and well, it's well worth another play trough, and even after that, another more, and another and another.
So in the end, Diablo 2:LOD is a great game you should at least give it a try, some minutes, some hours, some days, at some point either you'll love it, or you just won't like it that much.
And it's good to play it before Diablo 3 is released, getting used to how things work and what to expect.
By the way, i'm only reviewing the Offline Portion of the game "Online should be even greater" (personal thought).
[Addition]
What the hell? As they say, the expansion takes it time to shine but Whoa!, when it shines, you better cover your eyes or it might make you Blind, So yeah, i was enjoying the Diablo 2 Part of the Game, good as already said, But when i jumped over to Lord of Destruction, WHOA! Amazing, The Setting, The music (especially the music), the quests, it's awesome.
The Music, Whoa!, i enjoyed Diablo 2 Music, But Lord of Destruction... Just Whoa!, it went from Bad ass tu Ultra Bad Ass, i remember wondering if i was still playing that same game i had played for a while now when i listened to it, Totally amazing soundtrack.
Some neat surprises also.
Still a Great Game to play.
Enjoy it.