My favorite is It's Your World - the title song from his 1976 double album with Brian Jackson.
Another great album is Pieces of a Man from 1971, which features the musical masterpiece Home is Where the Hatred Is. Written by Gil, it was also made memorable by Esther Phillips who recorded her own version around the same time.
My favorite song from Pieces of a Man is Lady Day and John Coltrane.
Gil Scott's most famous tune is probably The Bottle from his 1974 Winter in America album.
One final favorite song is Willing from his 1980 album with Brian Jackson - here given the b'more touch by Top Billin.
Gil Scott-Heron (1949-2011), R.I.P.