I'm an Intel guy. Or, I was until now. I see that AMDs CPUs are almost catching up with single core performance.
And single core performance will get less important over time. Various tests suggest that Intel is still the king with most of the games, but this will flatten out.
If you're not chasing for an absolute high end gaming computer monster then it doesn't matter if you use Intel or AMD. And AMD right now might be more affordable.
Still a different thing with GPUs, though. Let's wait for those new AMD cards.
Karl