DVD video is interlaced. It looks normal in MPC because it's deinterlacing the video as it plays. In VLC that setting is turned off by default because videos made today are in a progressive format rather than in an interlaced format. You'll have to turn on that setting if you want the video to look normal in vlc. 

For some reason, one of my DVDs plays terribly in VLC, but great in MPC.

[Here is what I'm talking about](http://imgur.com/a/iD716).

Notice how the frames seem to overlap, and how the main character has grid-lines.

The DVD is basically unwatchable in VLC, but for some reason it works good in MPC.

Any explanation for this strange behavior?

[Video quality] Poor video quality in VLC, good in MPC...