AFnord: If you have any experience with rogue likes, you might have a basic idea of what Diablo is all about. You venture down into randomly generated dungeons, kill stuff, level up and get better equipment. Unlike most rogue likes the Diablo games are rather forgiving (there is a perma-death mode in diablo 2 though), and combat is more about action than tactics and planing. Also, unlike most rogue likes, the game won't just randomly punish you for believing that you could beat it (anyone who has ever played a real rogue like and died because of a missidentified healing potion knows what I'm talking about...).
You don't need to play Diablo 1 in order to enjoy Diablo 2. While Diablo 2 makes a few nods towards its predecessor (and there is one part in the first world that just won't mean anything to you unless you have played the first game), the games are not really about the story as much as it is about monster slaying.
Diablo 2 was, from a mechanics point of view, the stronger of the two games. It offers more variety, the classes each differ a lot more, there are more skills and abilities, combat flows better, but Diablo 1 just had a far better ambiance. I was disappointed with Diablo 2, because its locations (with only a few exceptions) failed to evoke any real feelings what so ever, and they felt too diverse, and as a result a bit incoherent. Diablo 1 on the other hand had a very oppressive feel to it. It was dark, the world felt threatening and far more fitting for its source material. Also, I thought the enemies looked far more intimidating.
In my opinion, the games gets far too repetitive. There is not enough variety in them compared to their length and they will start to feel like they overstay their welcome by around the halfway point (at least they did to me).
Getting the games is not hard. The old battle chest (which is what you want, don't buy the new one) costs $20 used on Amazon, and it will contain the original game (without its semi-official expansion) , and Diablo 2+expansion. You can also buy the games individually for between $5-$10. You want the expansion for Diablo 2. Getting the expansion for Diablo 1 is a bit more expensive ($15-$20 used), and I found it to be a bit of a mixed bag. Some new gameplay mechanics were quite good, others were not, and the new levels were inferior to the ones in the original game. If you can find it for a good price, pick it up, but don't go out of your way trying to get it.
very true and i must confess i had times when i was standing before the infamous butcher room and had an oh no moment will i beat this guy at all.