[the_tyrant]

CPUs make or break the system
Many believe that Video cards are the most important part of the system. It is NOT TRUE Video cards are important in gaming and 3d design, but everything else, CPUs are more important.
Also, back just a bit more than 3 years ago, there was a time when every Intel cpu used socket 775, and every AMD chip used am2
However, now there are different sockets for different CPUs. Bigger socket number= better cpu, and generally better board with more features.

as for core numbers, more is better, but for the same amount of money, i would rather get better instruction sets, lower heat etc.