Samsung Galaxy S3, which has recently won the title of "Best Android Smartphone" from almost all the leading tech reviewers, has landed on AT&T.

The celebrated Galaxy S3 packs in high-performing hardware and inspired software features.

With 4.8-inch HD Super AMOLED display, Gorilla Glass 2.0 to protect the display, Qualcomm Snapdragon S4 1.5 GHz dual-core processor, Ice Cream Sandwich OS, a 'personalized' 4G LTE connectivity and 2GB of RAM and the Human features, Galaxy S3 is indeed excellent and perhaps the biggest threat to all leading smartphones available in the market including the big-shots like HTC One X and iPhone 4S.

But Galaxy S3's first competitor would be the smartphones running on the same network, AT&T. Check out the list of top 5 smartphones running on AT&T network and going neck and neck with the Samsung Galaxy S3.

HTC One X

The HTC One X, the Taiwanese company's biggest bet is one of the very best smartphones that you find in the market. Featuring a monstrous yet 4.7-inch HD display which comes with 1280 x 720 pixel (720p) resolution, Qualcomm's next-generation Snapdragon S4 CPU, a 1.5-GHz dual-core chip, Adreno 225 GPU. 1GB RAM and 16GB of internal storage, the phone is all that you need to have in a smartphone.

While the phone is tall with 5.3 inches, One X is slim and light but sturdy with its 2.75-inch width, 0.36-inch thickness and 4.6-ounce weight. The company has opted for single piece of polycarbonate plastic body which gives One X a premium quality feel.

The camera of the phone is one of the major attractions. The 8-megapixel primary camera comes with HTC's "Image Chip," paired with Sense 4.0 which gives a lag-free shutter experience and lets you capture all the moments. One X provides photo and video capture buttons on the same screen, making it easy for the user to switch modes or simply snap a photo while recording HD at the same time.

Moreover, One X features HTC's Beats audio. AT&T describes the audio experience on One X as "good, better, best" - good as is, better with Beats headphones and best when plugged into Beats.

Average download speed with One X is an impressive 16.63Mbps and upload speed can go up to 15.83Mbps.

Get the phone for $199.

iPhone 4S

Apple's last iPhone, the iPhone 4S, is a new iPhone but just an upgrade. Nonetheless, the phone is also a legend with its Retina display, improved camera, faster processor, smarter antenna and 'Siri', the voice assistant.

The elegant iPhone 4S sports a 3.5-inch, 960 x 640-pixel IPS display, iOS 5 operating system, dual-core 1 GHz Cortex-A9 processor with PowerVR SGX543MP2 GPU, Apple A5 chipset and 512 MB RAM. the phone also comes with an 8 megapixel rear-facing LED flash camera with 1080p HD video capture capability and a front VGA camera with 480p video capture capability and video calling over Wi-Fi only.

The iPhone 4S gives 14.4 Mbps download speed and 5.8 Mbps upload speed and does not support 4G LTE. Apple also provides a Bluetooth version 4.0 with A2DP, USB 2.0 version and Wi-Fi 802.11 b/g/n and Wi-Fi hotspot with its last released iPhone 4S.

The AT&T price of the phone ranges between $199 to $725.

Nokia Lumia 900

Nokia's flagship Lumia phone was the biggest bet for the company to get its lost reign back but recent sales figure shows that the phone could not live up to the Nokia's expectation. But still the Windows Lumia 900 makes a solid impression and features in the list of best smartphones running on AT&T.

The 4.3-inch Lumia 900, ensconced in a polycarbonate body with a striking blue color, comes with dimensions of 127.8 (height) x 68.5 (width) x 11.5 (depth) mm and weighs 160 grams. The Nokia phone sports 800 x 480 pixels Super AMOLED Plus capacitive ClearBlack touch-screen with 217 ppi density. The phone also touts a versatile 8MP camera with Carl Zeiss optics.

On software side, Lumia 900 runs on the latest Microsoft Windows Phone 7.5 Mango (will get the 7.8 update soon), a 1.4 GHz Scorpion single-core processor, Qualcomm APQ8055 Snapdragon, Adreno 205 GPU with 16GB internal storage and 512MB RAM. And, no external microSD card slot.

The phone is available at a very affordable price of $99.99 on AT&T.

LG Nitro HD

LG's Nitro HD features a stunning 4.5-inch True HD AH-IPS display, Android 2.3 Gingerbread, 1.5GHz dual-core processor, 1GB of RAM, Adreno 220 GPU, an 8-megapixel rear camera, 1.3-megapixel camera for video chats, 1,830mAh battery, and 4GB of internal storage with a card slot to extend memory for up to 32GB.

The phone also supports 4G LTE.

The phone is available for $99.99 at AT&T.

Samsung Galaxy Note

Samsung's 'Phablet' is one of Samsung's most interesting offering in the recent past. The company claimed to have sold 5 million units globally in just five months after its launch in October. The phone packs in a 5.3-inch AMOLED display with 1280 X 800 pixels, TouchWiz UI version 4.0, 8 megapixels rear camera, 2 MP front camera for video calling and S Pen stylus.

On the software side, the Note features 1.5 GHz Scorpion dual-core processor, 16GB storage, 1 GB RAM and runs on Gingerbread. The phone also comes with Wi-Fi 802.11 a/b/g/n, Li-Ion 2500 mAh and AT&T's 4G LTE connectivity.

Galaxy Note is available at $299.99 for a 2-year contract.

Which smartphone in the mentioned list gets your vote to stand tall against the Samsung Galaxy S3? Let us know in the comment section.