Motorola Q -> iPhone -> iPhone 3G -> iPhone 3GS -> HTC Touch Pro -> Samsung Omnia -> BlackBerry Tour -> BlackBerry Storm 2 -> Droid
I had been pretty happy with the iPhone until it became imperitive at work that I have cell service inside the building. Basically, while Verizon has 5 bars inside, there is virtually zero AT&T signal inside the building. None. Nada. Maybe by a window, but otherwise zip. So by necessity I had to switch to Verizon.
As you can see, I basically worked my way though every smartphone VZW had to offer. But now that I've hit Android, I think I'm finally happy.
Besides, if I change phones again, my wife will kill me!