I would get a Windows phone personally. I'm using a HTC Charmer atm (T mobile MDA compact) which is pretty s**t as a PDA. But it has all the windows outlook features along with word, excel etc etc etc.
My next one might be this in a month or so.
http://www.expansys.com/p.aspx?i=132494
Has EVERYTHING. Keyboard which is useful if you've ever used the handwriting technique you'll know it's definately not the fastest way of entering text, and the on screen keyboards can be a little unforgiving at times.
It has the power of the latest PDAs which means games and movies will work like a charm. WiFi, Bluetooth means you're always online. Phone which works with the Outlook contacts will always be my reason for buying one. And this has GPS built in !!
Not the biggest screen you can get, but it's the same as a normal PDA with the keyboard function, so when watching video it can be less than optimal, but what do you expect from a 3 inch screen....