Johnny Cash is good for me to start with as I ease back into playing guitar. It's basically just three chords and the truth, so it's not technically difficult. I'm so rusty, though, even easy non-technical covers of the Man in Black sound pretty sad on my flat-top box. Give me a few weeks.
Plus, this Christmas, I'll have several classical-style arrangements of Christmas carols to play.
My guitar playing will sound so much better after I trim my fingernails.