Toshiba SD-P1600 Portable DVD Player with 7-Inch LCD
Hassle Free
No problems thus far, just took on a 2 week trip.  Battery power is about 2.5 hours.  Image quality is good.  Only complaint is the volume level -- both the internal speakers and the headphone jack don't get loud enough.  Seems to be a common complaint about portable DVD players -- not sure why it should be the case, though.