After I'm finished watching movie in VLC, usually an H.264 MKV, all of my memory is completely taken up by inactive memory. This is because VLC is causing the OS to catch all of the data that is read, something that isn't necessary.
This causes the OS to be fairly laggy, as writing to free memory is much faster than swapping out inactive memory. This can be solved with fcntl(F_NOCACHE)
I know of many other VLC users experiencing this same thing.