Far Cry - Volcano
Like our Doom 3 "heat haze" demo, the Volcano level in Far Cry includes lots of pixel shader warping and shimmering.

The 128MB Radeon X700 cards appear to be stricken by a bug at 1024x768, but even at higher resolutions, the GeForce 6600 GTs are easily faster. The Albatron GeForce 6600 pulls largely even with the vanilla Radeon X700 in our Volcano demo, too.