40 Greatest Hits is a two-record greatest hits compilation by American singer-songwriterHank Williams. It was released in 1978 by Mercury Records — who under PolyGram became responsible for the MGM tape vault — on the 25th year anniversary of Williams' death. Significantly, it was the first anthology in quite some time that did not subject Williams' recordings to either rechanneled stereo, posthumous overdubs, artificial duets with family members (like his son Hank Jr.), or most or all of the above. Because of both this, and the value-for-money attraction of having a deeper song selection than previous single-disc compilations issued previously by MGM Records, many reviewers consider this anthology to be the perfect starting point for newcomers to Williams' recorded legacy. The album remains, to this day, the best-selling record of Williams' career.