The "You" was the royal or collective you. 
Most people (AEP excepted) want the fastest drive they can afford. I'll say it again. As the slowest part of the system...
If you want quiet (silent), go SSD. Or there are noise reduction cases/enclosures.
SSD drives are the way to go.
I stuck an Intel 330 series 180 gigabyte SSD into my wife's laptop for £80 and the sheer jump in perceived speed made it looked like it was a whole new system.
Win 7 takes less than 10 secons to come up from power on to installing all the startup tasks including Kaspersky.
I have also stuck an Intel 520 series 480 gigabyte SSD into my new build high spec system for £350 and startup is also less than 10 seconds but I think this is now due as the disk doesn't access while the windows 7 animation is happening. if I could dump that animation I could take 2-3 seconds off that.
Intel SSD drives come with a 3 year warrenty on the 300 series and 5 years on the 500 series so Intel are confident on their product lasting and the closest HDD warrenty I have seen that matches that is my 3TB red NAS drive from WD with a 3 year warrenty.
I am running my system on a tri-boot with a relatively small 2gig swap file on each windows install and have all my programs on the SSD and have an external 2TB HDD drive in an Icy Box enclosure.for data.on an esata connection.
As for the OP's original question without knowing their full system spec I would say that more memory is better than faster memory for video editing, I had big problems with just 4gigabytes on my previous system using pinncle studio and the move to 8 gigabytes made a huge difference.
Also I would say going to a SSD for the windows install, swap files and programs and another HDD for data, rendering and video capturing. may give a very nice jump in percieved performance.
Also if the OP does a lot of video capturing it is recommened by the capture card manufacturers to capture onto a drive that doesn't have a windows swap file on it anyways.
So to summerise get a SSD drive (I would recommend Intel) and an upgrade to 8 gigs of DDR2 memory (although you will need to check to make sure your mobo can actually take that much) and I would think you will see a nice jump in performance.
Edited by deleted (Mon 10-Dec-12 14:46:10)