Depends.The Phenom is a quad-core, whereas the C2D is dual-core. The higher clockspeed and slightly more efficient architecure make the C2D better for single-or double-threaded programs (which currently includes most games and other programs), however, the 2 extra cores of the Phenom mean that when a program is using 3 or more threads the Phenom takes the gold(File compression tools such as WinRar, 7-Zip, UltimateZip etc., CPU-intensive graphics/multimedia editing software and some but currently very few games such as BioShock all utilize more than 2 threads). For gaming and general use the C2D is better, but depending on the price, it may be worth going for the Phenom as it's got higher potential.