Engadget: Despite the sweltering heat waves, our spirits are high at Engadget, and for good reason: it's time for our summer edition of the smartphone buyer's guide. Here, you'll find our top recommendations for the best smartphones across several US carriers, along with the best QWERTY and budget alternatives. In many ways, it's now easier than ever to find a world-class smartphone, but unless you've developed a strong brand preference, choosing one is likely more difficult than ever before. It's no secret that the HTC One X and Samsung Galaxy S III have firmly cemented themselves as the premier smartphones of the day, but if you're torn between the two, we'll reveal our preference in this latest installment. (Phones, Smartphone)