I played both Diablo games. I love playing one and I have no idea where 2 are in my things, but I loved it too. Of course, I was very different then. I didn't care much about story, and was happy with the good graphics, great number of interesting monsters and the challenge. But I must say, a game like Diablo does not entice me today. I am older, I learned to seek a good story on my games and to hate borderline OCD gameplay.
Diablo is a game about where lore doesn't play a very important element. All you need to know is that evil forces exists, where they are and go there and kill everything in your way. And by killing, I mean clicking with the mouse as fast as you can on the enemies at sight and keep your fingers on the keys of healing and mana potion to keep you alive long enough to slaughter your enemies.
My strategy on the games was simple, yet effective. Hit and run. I would usually put a Town Portal at a safe place in the dungeon, go there, kill a bit until I run out of potions, run to the portal, re-stock potions, repeat until all enemies are dead. Yes, I know, it is a coward strategy, but it worked.
Of course, good players should have better strategies, but I never bothered. Why change when you are winning? And now that I think about it, I would not pay to play Diablo today, if Diablo III ended up being the same games as the first ones in gameplay and presentation. Those kind of games don't appeal to me anymore.
The basic gameplay would bore me to hell. For more that you have n different skills and classes to use, the constant repetition would kill me today. For more that most games are repetitive in nature, I feel that Diablo do it to an extreme degree. The lack of story elements also is a no-no to me. Today, to me, games should either have imaginative gameplay and/or great stories. Diablo 1 and 2 have none.
I am pretty sure that people who have never played a Diablo game would find fun in Diablo III. The same way there is a lot of people who loves MMOs. But Diablo III seems to be fueled by everyone remembering the good old days of its predecessors. Nostalgia is very tricky, and can make you remember something as way better than they were. Both games gave me a great time and great fun, but I doubt I would be able to appreciate them right now. You know, like that cartoons you loved when you were seven years old and that if you see them now you would question how in the hell was you able to even tolerate such stupid things.
Diablo came in a time that dark games with lots of gore were a novelty. Every kid who wanted to be cool should have played it. But now, in a world where there is plenty of gore filled and dark games, I think that Diablo will succeed more on nostalgia than for something really great. I may be wrong here, and if chance appears I would love to give Diablo III a run.
But if today someone ask me if I will get Diablo III, I won't. if they ask me if the previous Diablo games were as good as people talk, I would say not quite. I think Diablo III will be one of those games were people will play more together than alone, using the game more as a social tool than just a game. The fun will come more of the interaction with others than from the game itself. Which is great, of course.
Unfortunately, since I had not played Diablo III, my opinion on the games must be based on its previous entries. The third game must be completely different than the old games. But if you never played Diablo before, I would recommend caution before jumping in the hype wagon and expend money on it. If you go unprepared, unaware of what the game really is, it could be a big disappointment.