Apple iPad 2
iPad 3 Releasing Wednesday? Does Your iPad 2 Really Need an Upgrade? Reuters

Tablets have become an integral part of our lives since they are the best alternatives to PCs and laptops.

Apple defined the benchmark for tablets with its iPad in April 2010, and since then it managed to hold on as the top seller in the market, closely followed by Samsung.

Following are our top 10 tablets of 2011:

iPad 2

iPad still has a commanding share in the tablet market, with its ease of use, up to 10 hours of battery life and wide range of apps. Apple, which unveiled the device on March 2, 2011, is 15 percent lighter and 33 percent thinner than its predecessor and comes in 16GB, 32GB and 64GB models.

iPad 2 runs on iOS 5 and comes with a 9.7-inch display, giving 1024 x 768 resolution at 132 pixels per inch. The tablet, which weighs 601 grams and 8.8mm thick, is powered by 1GHz dual-core Apple A5 chip. Apple fitted a 720p camera on the back and a VGA camera on the front for video calls, which Apple calls Facetime.

Samsung Galaxy Tab 10.1

Samsung Galaxy Tab 10.1, which weighs 565 grams and 8.6mm thick, is considered as the legitimate contender to iPad due to its good screen, 1GHz dual-core Nvidia Tegra 2 chip and runs on the latest Android 3.1 Honeycomb OS designed specifically for tablets.

The tablet's 1280 x 800 TFT LCD screen provides a resolution at 149 ppi and its 7000mAh battery provides video of up to 9 hours and music for up to 72 hours. The device also has a 3MP camera on the rear and 2MP camera on the front. The tablet comes in 16/32/64GB models.

Asus Eepad Transformer Prime

Asus has launched its Eee Pad Transformer Prime, the world's first tablet to feature Nvidia's Tegra 3 quad-core mobile processor. The tablet runs on the Android 3.2 Gingerbread operating system, with an upgrade to Android 4.0 Ice Cream Sandwich available at a later date. The device weighs 585 grams and is 8.38 mm thick.

The specifications include 10.1-inch LED backlit Super IPS+ screen at 1280x800 resolution, 8MP camera on rear with flash and 1.2MP front camera for video calling. The tablet, which comes in 32GB/64GB models, has a battery capacity of 25 Watt-hours (tablet only) for 12 hours of 720p video playback at 60 nits, 18 hours with keyboard dock attached.

Amazon Kindle Fire

Online retailer Amazon began shipping Kindle Fire tablet in mid--November. The device, which runs on Amazon's customized version of Android, has a 7-inch screen providing 1024 x 600 pixel resolution at 169 ppi. It weighs just 0.91 pounds and 11.4 mm thick.

In addition, Kindle Fire has a powerful dual-core processor, 8 GB of internal memory, Amazon's Silk browser. The battery will last for 8-hour continuous reading or 7.5-hour video playback.

The icing on the cake is Amazon's e-content and cloud computing services, supported by the Kindle e-book library, Web-based music and video stores. Though, the tablet lacks a 3G and a camera, it is one of the best-selling gadgets, courtesy its low price of $199.

Barnes & Nobles Nook Color

Barnes & Nobles Nook Color is the closest competitor to Kindle Fire and a color version of the Nook e-reader device. It is a 7-inch tablet offering 1024 x 600 pixel resolution at 169 ppi. It weighs 0.99 pounds and 12.2 mm thick.

The tablet, which runs on Android 2.2, has a Texas Instruments' ARM Cortex-A8 processor running at 800 MHz and offers 8GB internal memory, which is expandable via 32GB micro SD card. The Nook Color's battery allows reading for up to 8 hours.

Motorola Xoom

Motorola Xoom was the first tablet to be run on Android 3.0 (Honeycomb) operating system and later updated to Android 3.1. The tablet, which has a 10.1 inch display offering resolution of 1280x800 pixels, is powered by a dual-core 1GHz Nvidia Tegra 2 chip. In addition, the Xoom features a 5MP camera on the rear and 2MP camera on the front. Xoom weighs 730 grams and is 12.9 mm thick.

RIM PlayBook

PlayBook is a 7-inch tablet from Research In Motion, best known for their BlackBerry smartphones. The tablet runs on BlackBerry Tablet OS and comes in 16/32/64GB models. PlayBook sports a 1GHz dual-core TI OMAP chip, 5MP camera on the rear and 3MP camera on the back. It weights 425 grams and is 10mm thick.

Following several months of poor sales, RIM started discounting the price of Playbook from its original $499 retail price to $300 at many outlets in late September 2011. The price was further reduced to $199 at various retail outlets in both Canada and the U.S. in November due to apparent low market demand.

Acer Iconia Tab A500

The Acer Iconia A500 is a tablet computer from Acer with a 10.1-inch screen offering resolution of 800 x 1280 pixels at 149 ppi. The A500 runs on the Android Honeycomb operating system and has a dual-core 1GHz Nvidia Tegra 2 chip. The tablet features a 5MP camera on the back and a 2MP camera on the front. The tablet, which weighs 730 grams and is 13mm thick, comes with 16/32GB storage that can be expandable up to 32GB via microSD card.

HTC Flyer

Flyer is the HTC's 7-inch Android tablet running on Android Gingerbread juice and is powered by a Snapdragon 1.5 GHz single-core processor. Its 7-inch display has a screen resolution of 1024 x 600. It weighs 420 grams and is 13.2mm thick. Flyer, which has a 4000mAh battery, sports a 5MP rear camera and 1.3MP front camera.

HTC Flyer offers a strong differentiator as it offers a stylus which helps in note-taking. The technology is called HTC Scribe Technology which also uses a feature called Timemark which enables a user to capture the audio of a meeting in line with the written notes. Thus tapping on a word in the notes instantly takes a user to that exact place in time in the audio recording of the meeting.

HP Touchpad

Wonder why HP Touchpad is here in this list when the company itself scrapped the product less than 7 weeks of its release? HP Touchpad made its way due to its sheer specifications like decent webOS software, dual-core 1.2GHz Snapdragon chip, a 9.7-inch screen with resolution of 768 x 1024 pixels, 1GB of RAM and 1.3MP camera. The tablet weighs 740 grams and is 13.7mm thick.

The demand for the product was clearly evident when HP began selling it for $99 for 16GB model. The tablet is still available at some online retailers.