Now that you mention it, Blackmail is an atypical one. Maybe someone blackmailed him into singing Blackmail? (I'm being goofy now). It's like you say, he carefully chose songs that would mesh with the tone and beauty of his voice or the lyrics or "story" meant something to him and so you wonder if the words meant something to him at the time he was recording it. Or was it someone else's suggestion that he record it.
For songs that are my favorites..it's like you say, like trying to pick a favorite child. Almost impossible. I always love "I'll Always Love you" and other favorite is "Dialogue". I love the sweet story of that one and picture the two people taking a chance and heading out for a new future together. I know he didn't write that one but he sang it so convincingly that I could picture this scenario, with real people, in my head.
Also love "Unconditionally" and "Dirty Hands and Dirty Faces." I better stop now. I could list another 20.