The reason why Angry Video Game Nerd always drinks Rolling Rock is because it was the only beer James Rolfe had in his fridge at the time he made the first episode.
The fake diarrhea used most of the times in the series is a combination of chunky peanut butter and chocolate syrup.
The first two episodes were made in 2004 as a joke under the title "Bad NES Games". Mike Matei convinced James Rolfe to post the episodes online and continue the series in April 2006.
James Rolfe's then-girlfriend (now wife), April Rolfe (née Chmura), did the camera setup in earlier episodes before Liam Mulvey joined.
In the third Nerd's Game Room there is a door that is next to the stair case and the closet. That door leads to the studio space where the green screen filming takes place. It's also the area where James Rolfe keeps extra copies of games he ended up receiving from donations.