The answer to this is quite subjective. How can any art be called "the best" or "one of the best" in an objective sense? However, consensus helps to enlighten. Take a look:
http://www.planetbollywood.com/Poll/view.php?pollID=307& When this album first came out, I was skeptical at first with people raving about it to no end even though I liked it. But now, this beautiful album has become an important milestone in ARR's career and has cemented itself as a great highlight of his career IMO. It's a complete album in every respect and after listening, I never get the sense that something is missing, even though there's no pure instrumental. The album scores high both horizontally (variety, scope, length, diversity) and vertically (depth, sound, serious immersion, musical prowess, great lyrical value, exceptional singing, great interludes). I hope ARR himself realizes what a gem he's created here and how much it's appreciated.