Far Cry
Far Cry, run without AA or AF but with in-game settings turned up to very high, shows that midrange cards are still limited by pure shading/fillrate concerns when run with an Athlon 64 4000+. High-end cards show little performance degradation as we scale the resolution ladder.
All cards are hurt by 4x AA/8x AF. 1280x1024 is reasonably playable, although we'd knock down the image enhancement settings to 2x AA/4x AF in the more graphically intense sections of the game. Not bad going for a £125 silent graphics card.