Need to replace my computer

[Crashtopher]

My current PC (P4 1.5Ghz, 512 RAM, radeon 9200) has sucked for long enough, so it's time to upgrade. My FPS ranges from 30-40 at good times as goes down to 1 during heavy action. I'm sick of it.

So, time for a new PC.

First Question: AMD or Pentium? Seems like AMD is much cheaper than Pentium. Any drawbacks?

Anyway, I've never built a PC, and I don't really see the need to learn, so that leads me to my second question:

With all the places out there where I can buy a PC, who does the best job and stands behind their product? How about someone like ibuypower.com?

Thanks, Crashtopher