Probably because human beings are inherently closet sociopaths and are attracted to dark images and cathartic violence. We are afraid of our own nature yet drawn to it if that makes any sense.

Also, the game is fun and addicting with a great sense of progression.

Probably the 8800gt is the cheapest video card that would max diablo 3 but honestly I am not sure. Thats cards probably like less than $50 now I would imagine.

A word of advice. Its better to spend a little extra money and get something that will last you a while. I recommend something in the geforce 500 series or above. The 550 series seems like a pretty good value. The 560ti is quite a bit better still and will give you great performance in modern games. Anything faster than that is not worth it unless you are planning on a cpu and ram upgrade as well.

I cant believe this is a serious question.....