Which is the best operating system for playing games in early 2009 ?

[Nutty]

So I am going to partially change my config but I do not know what OS (XP or Vista) to install on my system which will mainly be used to play games, is the dilemma ... I would appreciate your opinion as to whether XP is still the best choice for playing today!

[Nihir]

Windows XP is generally better for games because it requires very less resource during the game play.

[kraal]

I would say go for Vista for playing games that supports the recent direct x10 if your graphics card supports. Also keep this in mind that any vista bought after mid July (9, I believe) you can go for free on Windows 7.

What is your system?

[Nutty]

Intel Core 2 Duo E6750 will be overclocking +3GHZ of the motherboard that I will receive.
HD4850 OC @ 690/1130
4GB DDR2 G. Skill PC6400

[kraal]

Based on the configs, get i7 with at least 4GB of ram, also I would say that 64-bit Vista is more appropriate than XP, it allows you to use all the potential of the machine. (multiGPU, DX10 ...)

On configs with a dual core, 2GB of RAM and a single GPU graphics card, I would recommend XP 32 bit but it will be a little lower than Vista.