The top three handsets in the U.S. for Q4 2011 were the iPhone 4S, the iPhone 4, and the iPhone 3GS in that order.
Ross Rubin, executive director, Connected Intelligence for The NPD Group said,
"Attracted by a faster processor, improved camera and the Siri speech-driven agent, most iPhone buyers paid a premium for the iPhone 4S, making it the top-selling handset in Q4. The iPhone 4S outsold the iPhone 4 by 75 percent, and outsold the iPhone 3GS, available for free on AT&T, five to one."
It should not be considered huge news that the iPhone in 3 variant were the top sellers. Android has never had a single handset that compares with iPhone-ish numbers (though Samsung's devices are starting to show real uptake), yet Google's platform has overall market lead because of a number of devices with varying form factors and styles. The Galaxy S II and Galaxy S 4G were No. 4 and No. 5 on the list of top sellers.
That's interesting because Android has been criticized for being more technical, something requiring more experienced users because of its relative complexity compared to iOS. Some of that translates to extreme power, such as with apps like Tasker, but it has been said to dissuade new users.
Rubin noted the new user uptake, saying:
“Android has been criticized for offering a more complex user experience than its competitors, but the company’s wide carrier support and large app selection is appealing to new smartphone customers. Android’s support of LTE at Verizon has also made it the exclusive choice for customers who want to take advantage of that carrier’s fastest network.”
The iPhone has yet to adopt LTE, though it is expected that this year's iPhone 5 will have LTE connectivity on both AT&T and Verizon, and perhaps even Sprint, which has begun transitioning from WiMax to LTE.