Been listening to some 60s music of late and I haven't done a covers edition in a while. This song was actually first released by Gladys Knight, but I think you'll agree that most people think of Marvin Gaye when you mention "Heard It Through the Grapevine."
My favorite cover is a bit long, but I love these guys as anyone who has suffered Karaoke night at The Dingo will attest. Here is CCR with their cover, and in my humble opinion, an improvement.
Regardless of which version you prefer, this is one of the all time great rock and roll songs.