When I play a movie the picture and sound gets "choppy" even with NEW dvds

You can try using another media player.If that does'nt work ,your DVD drive may be bad or need cleaning.Sometimes a bad ram chip can cause the video to mess up.Try playing a movie directly from your HDD downloaded from a website and see if its choppy if its not then its your DVD drive.If it is still choppy it could be the media player your using or it does'nt have enough ram memory/virtual memory.If you have XP change your virtual memory settings and the refresh rate in task manager.(Bring up task manager,go to view tab then update speed to HIGH).

If other things are all right, you can tell that your hardware is not powerful enough to play the videos correctly.

You can check more reasons and solutions for this issue:
Why does video play choppy on my computer?