Well, there's the C.O.P.S. machines.
One is a Commodore 64, another is an arcade machine, another is an automated telephone, and the last one is a Pong machine.
Then there is the Castlevania: Symphony of The Night reference with the save point.
The firewall that Sam & Max have to get through.
The "computer bug".
The "Reality 1.5" stage of the game that plays as a text adventure.
"Nauseatilinglycute.com" and "Bancolavadero.com", which are real websites, btw.
You should probably spoiler tag your post, Cyberlink.