Let me say this first. I'm kind of geeky when it comes to computers.
So with that said:
My favorite is the Zaurus. Followed closely by Toshiba and their "pocketWin" PDA. My least favorite is anything that runs Palm OS.
Now let me explain. For 1 year I ran PalmOS on a m505 Palm. Palm should not even call it PalmOS, it should be called PalmDB, because the only thing it is good for is database apps. Now if you want an overpriced stylish looking Address book, then the Palm is you choice.
Toshiba make a really nice PDA with built in wireless connectivity. That is the main thing I like about that. Plus it has a real OS running on an ARM chip. So it has power and functionality. And what is this ... you can actually program on it. Wow. Plus I like it's handwriting recognition software.
The reason I like the Zaurus so much, and eventually bought one to replace my Palm, is that I can do all this developmental work I wanted, I could view pdf's, html and eBooks, I could go wireless for about $125 more($399 for a wireless add on for the Palm m505, ha ....), and most of the software is open source with a real Unix OS underneath.
So there you have it. Take it for what it's worth, but I like my Zaurus. It is so much more than a PDA. Actually it is more like a miniature comuter. But of course, ultimately, the choice is yours.
Good Luck.
SA