We've posted a few videos from the Lore in a Minute team in the past, and their latest is Diablo III. Their newest clip will take you all the way through the original Diablo to the newest iteration, setting up the events in a way most people can understand.
Truth be told the lore in general is pretty basic for anyone that's familiar with angels and demons tales, but it's a nice refresher for newcomers.
Diablo III Auction House closing down on June 24 forever and ever, also forever
2:00 AM on 06.19.2014