Neil Diamond always has a special place for me. I don't really follow his career anymore or buy his records, but he was the first musical artist that I took to as a child. I think it was because of Song Sung Blue, it's just one of those songs that is easy for a child to like and understand. The live album Love at the Greek has a fun version of the song with guest stars Helen Reddy and Henry 'The Fonz' Winkler.
I think in his early music there is a great sincerity. You can hear that on the live album Hot August Night (1972) - a very pure singer/songwriter. Unfortunately he soon became very glittery and more commercial. His last good album of the seventies was Beautiful Noise I would say, after that he became very commercial - especially in the eighties. It's not that the songs weren't good anymore, it just all had a commercial sheen (but you can say that about a lot of music in the eighties - it feels shallow often, very over-produced and flat). They even tried to make him into an MTV style music video artist with Headed to the Future.
Unfortunately it recently was announced that he was diagnosed with Parkinson.