[connnnn]

Most high-end games these days are optimized for dual core. As far as I know there aren't any single cores that can compete with dual cores anymore, especially when you consider heat/power efficiency. And the prices are so low that dual core is really what makes sense right now.

Quad core on the other hand is totally unused in most games as of now. They'll typically just unload the background OS and running applications to the 3rd and 4th cores and run the game on the 1st and 2nd.

And as far as cases go, I found an Antec Nine Hundred case on sale, which I would highly recommend. It's running so cool that my CPU fan doesn't even run while the system is relatively idle (anything less intensive than Firefox), because the temperatures of the cores stay around 22-25 degrees C (according to TAT at least). Thermaltake's Armor series has also been highly recommended to me.

Personally I always try to find a case on sale, and ESPECIALLY look for free shipping. If you can find one on sale at a local store, you'll pay sales tax but it's still worth picking up. Buying a case online you can often pay $20-30 shipping if you don't find a site that ships for free.