But two new tablets from Amazon and Barnes and Noble are giving the iPad serious competition.
Consumer Reports just tested both.
Bookseller Barnes and Noble is known for its e-book readers, but the latest offering, the Nook Tablet, is its first foray into the world of tablet computers.
Amazon, which also has a successful line of e-book readers, announced its first tablet with much fanfare. It's called Kindle Fire.
The iPad is still the tablet to beat, dominating sales with more than two-thirds of the market. Consumer Reports tested the Kindle Fire and the Nook Tablet, along with more than 20 others.
"The Kindle Fire and the Nook Tablet are much lower priced than the iPad, but they're also more limited. And the screens are about three inches smaller," Paul Reynolds of Consumer Reports said.
Tests show both tablets do have very good screen quality, and they make it easy to get to a web browser, email and other content.
The differences? The Nook Tablet at $250 offers access to the Barnes and Noble store. It also has 16 gigs of capacity and a memory card slot.
The $200 Kindle Fire only has eight gigs of storage, but you can upload your content to the Amazon cloud for streaming to the device so storage is less of an issue. And a real plus - the Kindle Fire gives you access to all your Amazon content.
"Up until now, lower-priced tablet computers have been pretty unimpressive in our tests. These are the first models to give the iPad some serious competition," Reynolds said.
But the iPad is still the best option for those looking for the full tablet experience. It's pricey, starting at 500 dollars, but the big screen is great for movies and games. It also has a camera.
The 32-gig iPad 2 with Wi-Fi and 3-G is Consumer Reports' top-rated tablet.
When it comes to content for the Kindle Fire and the Nook Tablet, both have a proprietary app store. While these stores have fewer apps than you'll find on iTunes or in the Android market, there are still several thousand apps available in both, including a wide variety of magazines and newspapers as well as popular games such as Angry Birds.