In episode 5 in the room with the dead couple, if you talk to Kenny 5 times, you get this description of the lead programmer, Randy Tudor
In episode 4 there is a probable reference to the Back to the Future series. Marty is also taunted by this line.
The achievement for completing chapter 3 of episode 3 is a reference to Sam & Max Hit the Road
At the end of episode 2, there is a joke on the fan criticism of Carley's lack of knowledge about batteries in episode 1. She responds with "You'll never let me live that down, will you?"
The achievement for completing chapter 1 of episode 3 is a reference to the 1969 Frank Sinatra song "Goodbye (She Quietly Says)"
The achievement for completing chapter 4 of episode 2 is a reference to the 1967 drama film, "Guess Who's Coming to Dinner".
The second chapter achievement in episode 1 is a reference to the 1987 comedy adventure film "Adventures in Babysitting".
In episode 3, there is a bottle of Banang (from Sam & Max Season Two) in the cupholder in the RV
The seventh chapter achievement in the second episode of The Walking Dead is a line from Monkey Island 1
In episode 1, Doug is wearing a bearalope (from Graham Annable's Dank the Comic Creator webcomic) t-shirt. Doug is based on Doug Tabacco, former Telltale employee and former Mojo staffer. Also notice the subtle reference to an "easter egg hunt" (looking for hidden jokes) on the sign in the background. One of the signs also says "The IT Guy", referring to the fact that Doug was Telltale's IT (information technology) guy.
In episode 1 there's a reference to Law & Order, which was the franchise that Telltale had just made a series from before The Walking Dead