Hi Ho is right. The best video input I have seen on a DVD recorder is S-Video.
I use it on my Panasonic DVD recorder. I use my Dish DVR to record. When I watch a program or F1 race, I then record to dvd and edit out the commercials while watching/recording.
If I want a dvd movie copied, I have my brother do it on his computer with great results. Though he is not able to record every disc as many have protection enabled.