Diablo II (PC)For starters, Diablo II has twice as many character classes as the first game. Each of the six totally new classes have very distinct "builds" that you can pursue. This would carry over to World Of Warcraft, though I think that game does it a bit better because you can pay to re-jigger your skill point distribution at any point. As with WoW, two builds in Diablo II for the same class will play differently. The Druid class is probably the best case of this, since he can become a spellcaster, a frontline tank, a pet class, or some combination of these. Anyway, the addictive loot system of the original Diablo was back (and also better), but the new layer of figuring out builds and powerful skill combinations (especially with synergies letting certain skills boost others) gave the game greater depth.
Looking back at Blizzard's games, I don't think any was as well served by a sequel as Diablo. When I bought the Battle Chest of the series two or three years ago, I popped the original game in as a reminder of where the series had come from. The word 'archaic' doesn't begin to describe it. There are still the basic elements at work that make a Diablo game a Diablo game, but so many improvements and expanded concepts were added in Diablo II that I think it's easy to forget how much the sequel added and perfected. Raise the stakes with the expansion, Lord Of Destruction, and the difference is even more dramatic.
Depth is something that Diablo II isn't always noted for, but with the expansion especially the game had added so many new concepts and systems over the original that you always feel like there's something to do before you quit for the night. At the same time, there are more ways than ever to power-up your character, whether it's the customizable socketed items and matching jewels and runes, the companion 'mercenary' characters, the magic items and equipment that can boost your native skills and/or give you the skills of other classes, or the aforementioned skill synergies, you feel like if you're having a tough time it's probably your fault.
Looking ahead to Diablo III, there are some things I hope get changed or dropped. For starters, the Stamina system has got to go. The original Diablo moves at a snail's pace compared to Diablo II, but even in this game you were limited to a certain amount of running until you have to walk for a bit. Moreover, I've always hated the light radius aspect of the game. To a lot of people this is a crucial element of the series, especially in maintaining its dark and devilish atmosphere, but I would like to see the game's environments even if it's more "realistic" to have the dark/underground areas limit your view. A few other things come to mind: being able to pay to redistribute skill points, a better way of looting (I dunno about you, but after awhile it gets annoying to have to click on every stack of gold, and sometimes I accidentally pick stuff up that I didn't mean to), a more balanced approach to elemental resistances (and poison, oh god, the poison), and some more direct control over mercenaries/pets/summons.
Technically and mechanically, Diablo II is a fantastic game. Blizzard are brilliant at interfaces and controls, and I think it was with this game that their design sense really started to shine. The animations for characters, spells, and attacks are, by today's standards, a bit stiff looking, but still good considering their era. There's a certain indefinable personality to the way characters and enemies look and behave that's very Diablo. What's more, I wish all RPGs would take a cue from this game and make it so that your armor/equipment shows up on the characters. Part of the fun of the game is watching your character go from a barely clothed/armed scrub to a frightening bad ass. And as you progressively add more skills to your repertoire, Diablo II smartly uses a shortcut key system for selecting skills so that you're mostly using the mouse to control everything, hitting the number keys to guzzle potions and the F1 through F12 keys to select skills.
Graphically, there's a trade-off to Diablo II: it will run on pretty much any computer from the last nine years, but you're limited to a 800 X 600 resolution. It can take some getting used to if you're used to modern videogames and PC games, but once you're back in the swing you hardly care because the 'addictive' and 'fun' are forever but 'good looking' is ephemeral. As for sound and music, they're good but since you'll be playing the game for so long you'll probably do what I do and turn the music off entirely and listening to your own with the sound effects turned down.
The original Diablo may not have aged well, but Diablo II is as good as it was when it came out nine summers ago. In fact, I would argue that it's better than ever thanks to recent patches and re-tuning. Since Diablo III probably won't be out til next year (at the earliest), you may as well get re-addicted to the second one. By the time you emerge from your binge, shaking and thinner than you've been since high school, the sequel might be out.