I bought an AMD Phenom II X4 965 black edition processor last Christmas ... Save some $, and go with AMD.
Same here - AMD 965. I wanted a processor with a high-clock speed to maximize single-thread performance. AMD was way cheaper than Intel. Price was no object, until I saw how much Intel wanted for the extra 20% in speed. I could purchase another computer with the price difference.
This is not the application I use, but it is similar. It gives an idea of the available performance increase from purchasing faster processors:
http://www.tomshardware.com/charts/desktop-cpu-charts-2010/Archiving-WinZIP-14,2431.html
The Intel Q8300 is $159 and scores 402 (WinZip) and 12066 (3D Mark Vantage Overall).
The AMD 965 is $175 and scores 261 (WinZip) and 13527 (3D Mark Vantage Overall).
The Intel i7-975 XE is $1,275 and scores 221 (WinZip) and 16075 (3D Mark Vantage Overall).
The 6 Core Chips:
AMD 1090T is $239 and scores 14567 (3D Mark Vantage Overall).
Intel i7-980X is $1,139 and scores 17114 (3D Mark Vantage Overall).
Intel's price jumps 375% to 730% for 15 to 20% extra performance. Additionally, AMD has less expensive, and well proven motherboards. I bought AMD.