dual core (X2) only if you have to much money or do a lot of non-gaming multitasking.
for gaming the single cores are faster than the dual cores of the same type and i dont think that will change in the forseeable future.
I got a dual core HT style Pent 4 and my system setup will allow me to run the cores as separate processors or you can configure them to run as a single core processor with all resources controlled by it.
Yes, BF2 works a lot better with it turned off, but I loved being able to burn a DVD, listen to music, and download to my hearts content all at the same time.
