No. 1: iPhone

No other product or brand has developed a greater cult following than the iPhone. In 2011, Apple made joining that cult a lot easier.

After four years, the obsession has become the year’s most searched term on Yahoo!. Apple lowered prices, signed up more carriers, and made the iPhone a world phone. Although fanboys were disappointed there would be no iPhone 5 this year, the 4S upgrade was enough to spur record sales — again. If technology leaps and bounding sales weren’t enough, the iPhone got some credit in helping bring down regimes. It also symbolized the vision of Apple co-founder Steve Jobs, who died the day after the new phone was announced.

Most Valuable Company
In August, Apple’s popularity and increased sales made the company the most valuable in the world, as it surpassed Exxon’s $331 billion market cap at $337 billion. Its glory was short-lived, as Apple sank back to second place after a rare third-quarter earnings disappointment.

Even so, Apple generated the kind of fervor Exxon never had (unless you count the fury over the Exxon Valdez spill). For months, bloggers, industry experts, and consumers speculated that the next iPhone upgrade would be significant. Rumors flew over what the iPhone 5 would look like and offer, including a better camera, a bigger screen, and even mobile payment system technology.

But in the end, the newest iPhone didn’t get a number change but an additional letter, becoming the iPhone 4S. Apple hasn’t revealed what the S stands for, but many have guessed Siri, speed, storage, or Steve Jobs. The iPhone 4S set a company record, receiving more than a million preorders in 24 hours. Besides a host of new features, the iPhone 4S is available in an unlocked version, as well. Chinese mobile carrier China Mobile said it reached 10 million iPhones on its network without being a registered carrier.

The most talked-about 4S feature is Siri, a personal assistant that talks back to you. Using voice-recognition technology that adapts to your natural speech, Siri can respond to questions (searching the Web when it doesn’t know the answer), create location-based reminders, and even have a conversation with you when you’re bored, which has spun off a “Siri says the darnedest things” meme with websites, blogs, and articles.

Death of a visionary
The iPhone 4S arrived during a time of transition and mourning for Apple. Jobs had resigned just over a month before the launch of the iPhone 4S, and he passed away the day after the announcement. Tim Cook made his debut as CEO with the upgrade announcement and conducted the press conference without much of a glitch. Attendees noted, however, that without Jobs, the atmosphere wasn’t as electric as it had been in the past.

The iPhone’s global reach was clear when people tweeted condolences from as far as Asia and the Middle East. Fans made memorial sites at Apple Stores worldwide. It was noted that iPhones helped protestors in the Middle East record events to send to other countries and media outlets. The videos helped fuel discontent and to rally a world to their side. Apple’s decision to sell unlocked iPhones meant that international consumers would no longer need to turn to third-party auction sites to buy one.

After Jobs
Apple showed that it knew how to do business even without Jobs at the helm. The phone’s faster processing and download speeds were draining the battery too quickly. Apple acknowledged the problem soon after the launch and promised to release a software update.

Before users could even download the newest iOS update, though, rumors were again in full swing about what the iPhone 5 would be like. It’s said to have been the last project for Jobs, and significantly different than the current models.

The big question is whether Apple’s huge cult following can continue without Jobs behind the design and engineering. With the iPhone 5 rumored to arrive in early summer or fall 2012, fans and Apple investors are eagerly awaiting the release, hoping that the company will survive and even thrive without its visionary.

Caroline Kim is a producer for Yahoo! Finance. She’s been an online editor for the past few years in both general and financial news. Before joining Yahoo! in 2010, she was at the Associated Press. Follow her on Twitter: @c_kim