Instead of downloading, why not rip your rented DVD's. You always know what you get and you decide on the quality. I rip and use 700 or 850 Meg CD's to make my movies. To download movies I can't rent, I use WinMx. It's not as good as it's use to be because of an inner program used by some called MxMonitor. The program monitors your uploads and downloads, you never have to be there, but a real crap program because if a MxM user comes in your queue, you browse him, and if you find something you want from him, you place yourself to download it. Then you start the MxM user download and MxM starts yours....but if you are in queue in a MxM, you will never get started if the MxM user is not in your queue.
For the program I use it is called FairUse Wizard, you can get it using the P2P program of your choice and it is very easy to use.