As far as an "entertainment system", the PSP, by far. It also has potential for good games, but so far, the only really good ones are puzzlers. Once the sequel to GTA3 comes out, I'm sure it's popularity will go up, and with all of the UMD movies coming out, as well as it's MP3 functionality, it can go far.

As far as the DS goes, it is based on a gimmick, but that gimmick seems to be succeeding. While there are lots of bad games for the system, we are also seeing some promising titles coming out in the next few months, including online-enabled Mario Kart and Animal Crossing. Its kind of funny that the first systme made by Nintendo to go online is a handheld...