Magnavox MPD720 7-Inch Portable DVD Player
This is the one
I bought this Magnavox about six months ago, after lusting for a portable dvd player for two years, and after trying a Cyberhome which failed half the time.  The M'vox has been in almost constant use, including recently by a 3-year old hooked on Dora the Explorer, and is extremely reliable and strong.   Mine goes for over 3 hours on the battery.  I have no complaints, only praise.  It's everything I hoped it would be.  What a great toy for a movie junkie.