Eminem

Examples of Singing: "Hailie's Song," "Cleanin' Out My Closet," "Kim," "Puke" 
It's no small feat to strike a balance between singing about unconditionally loving one's daughter and threatening her mother on the same damn song, but Eminem likes to dance on thin lines.

Conclusion: About 95 percent of the time, Eminem is busy terrifying people with his minced words, and the singing gets saved for super personal subjects.