I just finished watching the 6 hour documentary MGM: When the Lion Roars that was included on the third discs of The Wizard of Oz blu-ray set and it was great! Patrick Stewart was a little too over the top for me but the documentary is a solid look at the complete history of this fabled studio from inception to it's demise. Highly recommended!
The video clip below was a highlight reel of sorts that was shown at the beginning of each 2 hour 'episode.'
The dvd is available by itself (for $24 from Amazon.com) or you can get it as the third disc in the Wizard of Oz blu-ray three-disc set, presently priced at $40 but I got it on sale for $14 a few weeks ago (as did a few of my readers when I mentioned the sale).