Paul Simon is phenomenal he knows his stuff
Steven Tyler still knows how to work the full range even after all these years which just blows me away
Josh Groban has a great voice, but I wonder if he is gonna be all artsy-fartsy for his life, or if he is going to delve into more light rock and take the quality up a notch... Sinatra style.
I will never say that any single one is best. There are just a ton that are incredible and I will continue to like groups that don't have much talent but I end up singing along anyway. Anyone for some more A-Ha?