With Fox’s “American Idol” sitting in temporary storage, where colorful elves are busily figuring out how to bring it back as something comfortably familiar but also sparkling and new, the best reality competition show on TV is now NBC’s “America’s Got Talent,” which has been excitingly super-charged with the addition to its judges’ panel this season of its executive producer and the former star of “American Idol,” Simon Cowell. Some might growl that NBC’s “The Voice” deserves the distinction of being referred to as the best, and I might agree if the second half of its seasons were as riveting as the first, when it is all about the judges spinning in their chairs rather than beloved contestants vocally shoving each other out of the competition. It just doesn’t flow right; as on “Idol” and “AGT,” and ABC’s “Dancing with the Stars” for that matter, each season of “The Voice” should build in every way from beginning to end, rather than breaking apart in the middle. In that regard “Talent” is tops. The first few weeks of the season provide their own kind of fun, as hundreds of potential contestants perform their hearts out in all kinds of ways – some so fine it is humbling, others so awful it is just plain cringe-inducing, and all of them engaging for anyone who may wish to identify early contenders for the show’s coveted semi-finals, which begin this week. And then there’s the annual Dunkin’ Donuts/”AGT” partnership, arguably the best integration of sponsor and series to be seen on television in years.