While the sheer number of available Android devices has resulted in the platform surpassing Apple's iOS in popularity, Apple's limited portfolio of devices remained popular even as customers looked forward to updated hardware that arrived last month in the form of the iPhone 4S. According to NPD, the iPhone 4 and 3GS continued to hold the top two positions in U.S. smartphone sales during the third quarter, leading a series of Android phones in the rankings.

Led by continued steady sales for Apple’s iPhones, the top five best-selling mobile phone handsets in Q3 were as follows: 

1. Apple iPhone 4 
2. Apple iPhone 3GS 
3. HTC EVO 4G 
4. Motorola Droid 3 
5. Samsung Intensity II

The ranking follows an identical showing for Apple during the second quarter, despite the iPhone 4 having been introduced in June 2010 and the iPhone 3GS launch dating all the way back to June 2009. 

Even with the introduction of the iPhone 4S last month, Apple is continuing to sell the iPhone 4 and iPhone 3GS as low-end devices, with an 8 GB iPhone 4 being offered for $99 on contract at all three major U.S. iPhone carriers and AT&T offering the 8 GB iPhone 3GS for free on contract.