Hank Williams has to be up there, too:
Are You Sure Hank Done It This Way? - Waylon Jennings
Long White Cadillac - The Blasters (later covered by Dwight Yoakam)
Whiskey Bent and Hell Bound - Hank Williams, Jr.
Family Tradition - Hank Williams, Jr.
The Ride - David Allen Coe
Midnight In Montgomery - Alan Jackson
The Night Hank Williams Came to Town - Johnny Cash
Has Anybody Here Seen Hank? - The Waterboys
200 More Miles - Cowboy Junkies
…among many others