In addition to being a righteous protest singer and a funk pioneer, Marvin Gaye was Motown's great poet of love. In the '60s, Gaye made you feel the sweetness of love and the power of devotion, especially on his string of uplifting duets with Tammi Terrell. In the '70s, Gaye's love songs grew more sensual and explicit, but they're also deeply spiritual, shockingly personal and intensely moving.