LH, perhaps I should clarify my Dylan remark. I meant, he hasn't come up with a lot of really nice, memorable and unique progressions in all his many years of cranking out guitar accompaniments. He's not a big "classic riff guy". But there are some--a few which come to mind, at the risk of thread creep, are:

• Don't think twice, it's alright
  
• Mama, you've been on my mind
  
• You ain't goin nowhere, which sounds nice the first hundred times you hear it, until the outstanding repetitiveness gets to you.
  

W-O
get my mind off of wintertime...