Enemy Territory: Quake Wars
Things are more even in Enemy Territory: Quake Wars, however, and the Ā£98 Sapphire Radeon HD 3870 512MiB gives as good as it gets from the pair of overclocked GeForce 9600 GTs.
The graphs also show the difficulties that cards equipped with a 256MiB frame-buffer experience as resolution is increased - 512MiB should be a minimum, really.