OS Exploration: Windows XP Professional x64 Edition (Best Version Of XP)
This is Windows XP Pro x64 Edition. This version of XP unlike the standard x86 edition is built on Windows Server 2003. So overall it performs much better than regular XP, both in terms of speed and stability. The issues with this OS though, it does not support many drivers made for XP. It also has compatibility issues with some applications, like the latest version of iTunes will not install without a patch.