3800+ Athlon 64 X2 Dual Core
2 GB system memory
GeForce 8500GT 256 mb Video Memory

I hope that's enough. When The Sims 2 came out I found out the hard way that the game was a resource hog... I was running this system.

AMD 2200+
655 System Ram
Geforce LE 6100

The game did run, but it slowed down a lot when a lot of Sims showed up, or when the weather got intense. >_<