Yeah, last summer I was considering building an AMD X dual core system...with the super PCI express etc. After reading and researching, I just got the iMac 20 Intel dual core. Haven't been disappointed. Yeah, it has crashed a couple times playing video games but so does my XP box. I just turn off the dual monitor and it stays up.
So now, I have my XP box to record TV programs and my wife does email and bills and stuff.
I just personally prefer the wide range customizablity you get with a PC.
Now if there is one OS I would like to see again is the BeOS, it was very smooth and quick but nobody supported it.