It's another thumbs up for the Android option from me. The iPhone is triumph of marketing over functionality and the Blackberry is a bit formal.
Thanks to the open source nature of the OS, Android looks set to give the user real freedom of choice as to how they use their device rather than trying to control it as the other players seem intent on doing.
Incidentally, I have an HTC Desire HD and can't fault either the hardware of the HTC Sense front end.
I notice you didn't mention the Windows Phone 7 option, but then it's not worthy of mention as it's so truly horrible.