CPU: Intel Q6600 Core 2 Quad.
RAM: 4GB. PC2-6400 is cheap. Buy 2x2GB sticks to give you room to upgrade as the price premium over 4x1GB sticks is tiny.
Graphics Card: 512MB Nvidia 8800GT or 512MB Nvidia 8800GTS if you can push to it. Don't get the 320MB or 640MB version of the 8800GTS.
Wife: Best to get one that secretly thinks your geekiness is quite endearing and appreciates the fact that at least you're not down the pub.