DEFINITELY and WITHOUT ANY HESITATE, I will answer: it’s iPhone 3G.
GPS (esp. needed for someone), camera, multi-touch, 3G speed, … beside these highlights in hardware, the iPhone software 2.0 offers well-developed SDK, which makes user develop their own programs easily and more funny.
"It’s amazing!", as Steve Jobs said. (Strong recommend the keynote from this year’s WWDC)
A bad news is about Steve Jobs’s health, which says his tumor got serious again. His sick-looking from the release conference seems to evidence the rumor. So sad if it’s true. Steve is really the soul leader for Apple, and for us. God bless him.