I'm sure the intel fanbois
will be here soon urging you to get an i7 rig. TBH it is better but the cost will cause other parts to be skimped on, making up for the difference, so the PII would be faster. If you are strictly using this as a gaming machine, PII is better though. I might be surprised though, so BRING IT ON!!!! lol.
Coming from a Pentium 4, the 955 will rip through everything though.