Thanks for your recommendation.
I agree, however I also think it depends on the kind of processing you do with your computer. In a multitask environment the RAM memory is very important since it will begin to slow down the computer drastically when the RAM memory is exceeded. That's why a fast hard drive is so important, because when the memory starts swapping on the disk the difference in performance is huge between a slow and a fast disk. I recommend hard drives with native command queuing to speed up the multithread processing in the OS.
Generally I think the best way of having a fast computer is to constantly upgrade the harddrive to a larger and faster one when a certain % (e.g.40%) of the hard drive space is full and upgrade the CPU and memory when the upgrading of the hard drive is not helping enough anymore. In this way you don't need to upgrade the CPU and memory so often and you save a lot of bucks.
Best regards,
YamahaAndy