Pioneer PDV-LC10 Portable DVD Player
This is my favorite piece of equipment
The LC10 is completely, uterly, hopelessly, rediculously, awesome.  It has excellent screen quality, the built in speakers do the job but, I would recomend getting a pair of nice headphones and maybe a headphone jack splitter to use with it.  Extra batteries are a little expensive but they're worth it.  With my extra battery I can get 7 hours of play time out of my player.  The controls are intuitive, and easy to follow.  This is just a well designed, well though out piece of equipment that is a god send to have. It also looks great when hooked up to a large tv.