The Panasonic portables are good. I've been using the DVD-L86 for the past three years and it hasn't let me down. This model has the large capacity battery. You can get the (edit) LS83 for less - it is the same unit but without the large capacity battery. Both are selling for almost half the price now compared to when I bought the L86 in 2008.
I'd suggest a Sony. I tried several black Friday specials and they all had issues within a year(my kids are kind of tough on them) but last year I paid a little more for a Sony. It seems to be built much better than the no-name models. I paid $85 at Amazon but they went on sale locally a month after for as low as $69 at the time they were $100 locally + tax. I think Sony is changing models and getting rid of last years stock, I got the DVP-FX750.
I've also notice Panasonic seems to be clearincing out their portable BR player. It's 9"(my Sony is 7") and I believe it's <$130 now. I don't have BR but for those that do, it might be nice.
I like the Sonys because they have many of the nice feature of Sony home players, Panasonic is also a good brand but I have no experience with their portables.
Again I'd shy away from the off brand names, it just isn't worth the hassle if you ask me.
If you ever look again you may want to consider the Panny. One of the reasons I got it is because it plays DVD-RAM. I recorded all of my wife's cooking shows on RAM media and the player is primarily used by her.
That is one nice + of the Panasonics but it's my Kids that mainly use the portable and I put everything on either -R or RWs for them. I wouldn't trust them with my Panasonic RAM discs that cost a fair amount more than RWs and are much harder to find
I have noticed though that some of the Panasonic portable DVD players don't advertise on the box that they support RAM anymore. I've often wondered if they still do but just don't advertise it since RAM is so relatively unknown.
If the OP is interested in RAM playback note the Sonys do NOT support that format, Panasonic is probably your only choice.