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.
gaming, however, i'm quite taken with Intel. Bulldozer isn't too bad, tho, depending on the game. it "keeps up with" Intel @ 1080p and beyond on most games