Far Cry
Here the X2 sees a 10 FPS gain over the 2.2 GHz Venice -- most likely for the same reasons I detailed in Call of Duty post-discussion. Following the Venice close behind is the 3.6 GHz Prescott, while our 2.8 GHz Pentium 4s are once again in last place.
Halo
Halo is a bit of an odd case. The 3.6 GHz Prescott and Athlon 64s are basically tied, with the Pentium 4 670 at 2.8 GHz taking a definite 4th. The Pentium D 820 seems to take somewhat of a hit here, with a 5 FPS loss over the 670.
Half-Life 2
Half-Life 2 more or less mirrors Halo results, though this time the Pentium D 820 doesn't take a hit over the underclocked 670.