17. Blake Shelton and Ashley Monroe, "Lonely Tonight"
The second single from Shelton's chart-topping Bringing Back the Sunshine serves as a plaintive call and response between two ex-lovers who aren't good for each other anymore, but aren't yet ready to move on. The power ballad's sweet vulnerability — and the fact that there is no happy ending, just a temporary break from the loneliness — sets it apart from typical booty-call songs. No one, not even Shelton or Monroe, believes it when they sing that it's for "one more, one last time."