I Prefer Open Source Softwares, its applicable even for Operating systems, but as far as Windows XP goes, Its a Stable Operating System from Microsoft and Suits todays Internet Enviroment because it comes (on with Windows XP Service Pack 2) with Firewalls and Other Security Features.
I am looking for Mac OS X the only disadvantage is its Price, so we have Linux/Unix however they are not GUI based.
The Great Features of Windows XP Pro with SP2 are:
Security Features, including Firewall.
GUI based as with other Windows OS.
Latest Internet Explore and Windows Media Player (However I had replaced both with Opera browser and WinAmp Player as MicroSoft Product are Huge System Resource Consuming)
Good Interface (at the cost of System resource)
For Todays Systems with minimum od 128 MB RAM; more than 40GB Hard disk, Windows XP is an Good Option, if you want to Stick to Microsoft Products. But I hate to.
From the Reviews of MAC Operating System I am looking to for a Dual-boot. Also looking for the Release of Vista OS.