Hey Jim, such a tough question!!! I don't think I can answer with just one but here are a few that come to mind:
Black Crowes - Hard To Handle
I Aint Got You - Yardbirds
Spoonful - Cream
Close To You - SRV
Every Day I Have The Blues - BB King
All of these songs have killer blues rhythms, and leads -- plenty of licks and riffs to dive into here!
Mike
Keep rockin!
Mike Olekshy
GT Guitar Coach