Panasonic DVD-LS50 7-Inch Portable DVD Player
light, well-built, great performance, features and battery
I bought this after noticing that the DVD player rental chain  in many airports uses Panasonics exclusively, which to me says something about durability.  Comparing this unit with Audiovox, Mintek and Magnavox, it is obviously much more solid.  The great thing, though, is that for the same screen size, the unit is slimmer and lighter.  The swivel screen makes it very easy to hang on the back of the driver's seat in the car for kids to watch, since it folds flat and won't protrude from the seat back.  Others have noted short battery life.  I took it on a plane trip from Alaska to Arizona and watched all of the extended version of The Two Towers (over 3.5 hours) and didn't run out of battery.  I turned the brightness all the way down, but the picture was still very clear and easy to see in a darkened airplane.  The great thing is that the battery is much smaller and lighter than other DVD players I've seen, and doesn't really add to the size or weight of the unit.  This thing is great for viewing my CR-RWs with lots of family photos on them, as well as listening to MP3s or WMAs (it even recognizes playlists, although I haven't tried this out yet).  The controls on the player allow you to easily operate it without the remote, except for specialized functions.  With the free case and airplane/car power adapter offer through Amazon (I'm still waiting for mine), and Amazon's great price, you just can't lose with this.  The only thing the Mintek has that this doesn't is A/V input, but if you don't need to play video games on it, it's not a problem.  Don't waste your money on a slightly cheaper unit that doesn't even compare with this.  You'll be glad you spent a little more.