Intel or AMD :: OC or Stock Clock

That depends of the CPU that you have, usually AMD has the BE line, that can be overclocked easily rising the CPU mutliplier while the i7 line only can be overclocked using the FBS and BCLK.

AMD Black Editions are painfully easy to overclock.. much more so than the Intel rivals. My AMD 1090T has an unlocked multiplier, so I simply increased that along with the voltage to keep it stable.

Value for money, AMD will always beat Intel (and it's been that way for bloody years). My 1090T at 4.0GHz rivals Intel's top CPU quite nicely, but only put me back £200 instead of the £700 price tag the Intel demands.

That's what I was thinking. But it's "painfully" easy?

An easy way to get your feet wet with AMD CPUs is their Overdrive utility, which allows you to change and monitor settings using a nice graphical interface inside windows. I don't know if there is a comparable utility from intel, but if there is I haven't heard of it.
As to whether the overclock will increase FPS, that depends mostly on two things: the games you are playing, and how powerful your CPU is compared to your graphics card. Generally, top AMD CPUs can keep just about any graphics card fed, but if you are looking for a high end system Intel is the way to go if you're not into extreme overclocking. Or even if you are  

I have two GTX 260s in SLI x16x16, yet I still noticed a nice 8FPS increase in Crysis and 5FPS increase in Hot Pursuit when overclocking my CPU from 3.2GHz to 4.0GHz.

It's pretty easy with a BE from AMD. Just go to your BIOS, disable somethings and look for multiplier option, rise it and enjoy it.

btw, I only recommend use AOD for rise the multiplier, the voltage and other things must be changed from the BIOS.

The funny thing is that, for me, the multiplier option is the one thing which doesn't work in AOD. I can't set my 955 to anything higher than in BIOS, though I used to be able to. I haven't bothered to track down the problem. Another thing which I have been able to successfully change with it is the hypertransport reference clock. I agree about leaving the voltages alone, though.

That's is a problem not accepted yet. Uninstall your current AOD version, after that go here and download the AOD version 3.2.1, install it and start the software. When you start AOD, you will get a pop-up that says "A new version is available, download now?", just DON'T do it.

Thanks, I'll try it