Also stick to QUALITY media. Cheap DVDs can go bad in a few months. I only buy Made in Japan media. You can find MIJ media under the Fuji, Maxell, and Sony names.
It's also very difficult to discern between the ORIGINAL and COPY if you only compress the movie by 10 to 15%. Some "shrink" programs use detailed analysis to further improve the picture quality. In my personal experience, it's more efficient to split the movie if I have to compress by more than 20%. The benefit, of course, is that you can always rejoin the movie when high density media becomes much cheaper.