i willnot go into specific handsets but rather what makes the handsets work the system and support.
Nokia is full of Sh*t and the fact that most of their handset uses apps from ovi store which is a child company of nokia tells one how shitty it will remain.
fact 2 is that most nokia uses custom os which is hardcoded to the chips and any attemt to root it will be a total failure unless u are a rocket electronics scientist...
Iphones are good I havent had much with it but based on popularity i can say they area safe bet if you want to blindly buy a good smart phone.
smart phones running windows mobile or ce are also good. if ur working and have alot off typing to do home and away i suggest any windows based smart phone but what is the essence of carryin your office everywhere yet its games are so dumb
now the great ones are Android 2.2 + running or Blackberrys infact with the cheapest of the androids u can manage ur website ban stupid users (lol) and move threads etc etc... also its open source hence if youare bored you can root your smartphones OS then tweak it a bit (but most end upruining it this way) and again being linux based you can walk around the system and find how to make it unique to your taste. again there are alot of apps online to support androids infact there are close to 5 sites which offer downloads of apps other than the android market place and appbrain...
Now blackberry is another goldmine. its too goood to pass with gizmos which are loaded within it you can take down the etire internet if you want to using a blackberry. its internetworking speeds are off the charts and it gets better its also supported by a large community ence lots of apps
downside... Hardcoded OS
hope this will make your decision easier