A lot of people dont know this but may have found it annoying playing 'Xbox Original' games and having the picture squared in the centre of the TV screen. I realised the solution simply by accident.
Change the xbox display settings to '480p'
Simple. You'll want to change it back to 720p or 1080p to play 360 games, but for 'Originals' in 480p theres no loss of resolution, and no annoying empty black space either side of the Tv screen.