This post was part of Wikipedia but seems to have vanished recently due to the Epic Games free games database being removed, a few services have opted to preserve the information and I figured meh why not so here it is, everything Games with Gold ever.
The original Xbox and 360 Games list can be found here, the Xbox One Games list here and videos where applicable for the releases here
2016
January
no video found, Major Nelson Article here
February
no video found, Major Nelson Article here
March
April
May
June
age restricted, probably only playable on YouTube.
July
August
September
October
November
December
age restricted, probably only playable on YouTube.