That's sort of like asking, "Is the Ferrari 458 Italia the best sports car for driving enthusiasts?"
There is more than one well-equipped image processing application on the market and the "best" one depends on a number of factors.
Some people consider Adobe Photoshop Elements to be "the best" but others say Lightroom, CS5, Corel PaintShop Photo Pro, Capture NX2, Bibble 5, etc.
I've used all the ones I just mentioned as well as some others I don't care to mention. For me, CS5 is the best, but I recognize that other applications have strong points as well. For example, I personally find the lens correction tools in Bibble 5 are better than the various Adobe offerings and it's easier to do some creative edits in Corel PaintShop Photo Pro than it is in PS Elements or CS5.