Call of Duty 4
This game is about as sweet as they come, and we also tested it manually using FRAPS. We played through a portion of the "Blackout" mission at 1600x1200 with 4X antialiasing and 16X aniso.

Here the HD 3870 again performs pretty much identically to the Radeon HD 2900 XT. Are we detecting a pattern? (Lightbulb appears in thought balloon. Ding!) Unfortunately for AMD, that's not enough performance to keep up with the 8800 GT.

Meanwhile, the HD 3850 continues to struggle with CrossFire scaling. The 2900 XT doesn't scale well here, either, though.

TimeShift
This game may be a bizarrely derivative remix of Half-Life 2 and F.E.A.R., but's it's a guilty-pleasure delight for FPS enthusiasts that has a very "action-arcade" kind of feel to it. Like most of the other games, we played this one manually and recorded frame rates with FRAPS. We had all of the in-game quality settings maxed out here, save for "Projected Shadows," since that feature only works on Nvidia cards.

Another game shows us a similar pattern. The HD 3870 is fast, but not as fast as the 8800 GT—yet it's delivering what feels to me like playable performance at 1920x1200 with 16X aniso. The HD 3850 can't quite handle this resolution as gracefully.