Despite the challengers, Apple's iPhone remains the best smartphone available. The newest version -- the iPhone 4S -- adds faster hardware, a much better camera, and the Siri voice-controlled personal assistant to what was already the most capable device on the market. The wealth of business and personal apps, the diverse media and gaming options, and the enterprise-class security capabilities as a complete package can't be beat. The previous model, the iPhone 4, remains available for $100 less and is a great option for more casual users.
U.S. carriers: AT&T Wireless, Sprint, Verizon Wireless
Price: $199 (8GB), $299 (32GB), and $399 (64GB) with two-year contract; $649, $749, and $849, respectively, for unlocked, no-contract versions