launch day games i've tried with no issues on my 5870 include BF3 (includling "paid beta"), Sup Com 2, Starcraft 2a, Portal 2, Crysis 2 trial, NFS: Shift, Metal Gear Rising, Borderlands 2, Skyrim*, Train Simulator 2014* (* = launch + 1 month)
only issues i've had were a few demoscene nvidia-favoring demos and bitcoin-related OpenCL driver combinations.
off-scene/pouet, there's Separable Subsurface Scattering (Real Time). semi-raytracingish, there's Rigid Gems
...however i am not good at summarizing, either.
i always bring up launch day/early access games i haven't had issues with: the Crysis 2 demo, Starcraft 2, BF3, NFS: Shift, Alan Wake, Supcom 2. sadly, i was a bit late with Skyrim, getting in at v1.2.
this made me wonder if the Pi supports monitors without HDCP (btw, it SEEMS to). for example, the Boxee is notorious for not liking HDCP-less monitors.
if you can hear the difference, well, i tip my hat.