Polaroid PDV-0700 7" Portable DVD Player
Polaroid PDV 0700 does the job
If you're looking with a relatively inexpensive portable dvd player with great battery life, this is a good choice.  It's easy to use (my 5 and 7 year olds have no problem) and pretty durable.  Sound is adequate and picture is okay (widescreen).  But I bought it for convenience, decent picture size, and battery life.  Use good headphones.  They'll help a lot.