Do you have your PageFile Disabled?
If so you should re-enable it. There is nothing to be gained by disabling it, and may in fact cause issues.
On occasion some applications can cause problems if there is n PF one found.
With 8GB of RAM, it should ideally look something like this:
Notice the Free Space is 0?
This means Windows is actually using all the RAM to its full potential.
As already mentioned, Standby should not cause any issues.
Its basically just DATA you have used, or Windows think you will use. When you launch a program thats been cached to Standby mode, it instantly gets turned into "In Use".
This means it doesn't need to access the HD for the info, making it faster and more responsive.
On the other hand, if you start a program that needs more memory, it can instantly dump the oldest items out of standby to make room.
It's much more efficient letting Windows manage it. I mean, why have that much memory if you do not want it to be used?