Just to wake this thread up again, here's what I've added since posting the list back in 2012:
Alan Jackson - It's 5 O'Clock Somewhere
Arlo Guthrie - City Of New Orleans
Bill Haley and his Comets - Rock Around the Clock
Blake Shelton - Honey Bee
Elvis Presley - Return to Sender
Everly Brothers - Wake Up Little Susie
Foo Fighters - Learn to Fly
Jackson Browne - Doctor My Eyes
Jimmy Buffett - Come Monday
John Denver - Annie's Song, Country Roads, Thank God I'm a Country Boy
John Prine - Please Don't Bury Me
Loggins & Messina - Danny's Song, House at Pooh Corner, My Music
Merle Haggard - Mama Tried
Ricky Nelson - Hello Mary Lou
Sammy Kershaw - She Don't Know She's Beautiful
Willie Nelson - On the Road Again
Instrumentals (Sax) - Ain't Misbehavin', All of Me, The More I See You, Night Train, Satin Doll, Summer Samba, Sweet Georgia Brown, Under the Boardwalk