If you want top performance today it would be an Extreme Edition P4. In 32bit apps the Extreme wastes the fx series AMD's. 64bit different story but I said "today" save your money and wait for Intel's new CPU's with 64bit extensions and Intel will again be on top. Price shouldn't be a huge issue as the new design gets more cuts out of a sheet of silicon. It will be a back and forth topic... But Intel has more resources and funding behind them, so if they want they can always win.