I am a fairly high user, so postpaid is it for me.
Had a quick squizz through the list and all phones are within my budget (although obviously price is a factor, functionality is more important).
features I regard as very important:
Good Camera (video taking, playback and upload to youtube is important as I like to take impromptu videos of the kiddies for the grandparents)
Good Email cpabilities for work
Intuitive UI/OS
Easy to use music player (with decent storage capacity)
Features that would be nice, but not essential:
qwerty keyboard
bluetooth
Wifi
good map/GPS interface.
so far I like the Sony W995, the Nokia N85 (although that does seem a bit expensive - are there any major benefits to paying that much extra as it seems very similar to the W995 which is half the price almost?). I also like the N75 for it's slide out keyboard. possibly Nokia E71
Blackberry is a maybe, although I have never used one before.
(of course another option is to wait for the new iPhone - which looks damn impressive, not sure about using a touch screen exclusively though)
speaking of touch screens, the Samsung 480 seems great value - anyone used the touch screen on that?