Here's a link from a performance back in the late 90s (same year I saw him) and it's wonderful listening to him interact with the crowd. It's what I remember most about his show.
Would that have been before or after he had throat cancer? In interviews he would talk about how after the surgery his voice sounded different and in his opinion, better. I tend to agree. I like his earlier stuff but I think his singing voice post-cancer had a little more grit and not quite as much twang, and his music was the better for it.