Critical Role
Critical Role is a web-video series that airs on a weekly basis, and is based on the streaming of a game of Dungeons & Dragons played by a group of famous voice actors, most notably Matthew Mercer as the Dungeon Master. It has been held up as being a huge part of the reason why Dungeons & Dragons 5th Edition was such a commercial success, as this publicity gave D&D a huge public image makeover, allowing it to be officially perceived as "cool", and not the province of emotionally stunted, socially inept, hideously deformed basement-dwelling nerds.
The Setting
The players of Critical Role use Mercer's own homebrewed world, called Exandria; the first campaign (series) takes place on a continent called Tal'dorei, whilst the second takes place on another one called Wildemount. The second campaign is set 20 years after the events of the first.
The Crunch
Critical Role began as a Pathfinder game, and then moved to Dungeons & Dragons 5th Edition with some homebrewed mechanics, most notably the existence of a Gunslinger class.
Mercer may also be familiar with Dungeons & Dragons 4th Edition, as certain influences from the Nentir Vale can be seen on Tal'dorei - most notably, the Tal'dorei pantheon is literally the Dawn War pantheon, but given new names.
In 2017, Mercer officially released a Tal'dorei campaign setting splatbook for 5th edition. He has also brought up the idea of doing other splatbooks for different parts of Exandria.