I like his singing.
I am a big Dylan fan, his song/poetry skills are excellent. I do enjoy his singing as well, but often times a Dylan song in the hands of another can be excellent, as well as better than Bob (sorry, Bob).
You mention "Watchtower", that is at the top of everyone's list.
This one deserve to be near the top: "I want you" - Sophie B. Hawkins (From Bob fest)
Excellent, as well as sensual.