Without a moments hesitation, I can (and often do) recommend the Pilot -- no I don't work for Palm (or any other division of 3Com) :-)

I am reviews editor at a computer magazine, and so, trust me when I say that I play with a lot of gadgets. I've tried them all and have always gone back to my Pilot. It's extremely simple to use, well designed and has a huge third party following -- there are thousands of really neat applications (many share- and freeware).