If you look carefully, each episode contains a randomly placed image of a pickle,
Almost every, if not all, episodes contain an image of Huggle Bunny(i.e. in a picture, in character, etc.)
Lundgren, the town where Sanjay and Craig live, was confirmed in the Christmas special to have been named by the famous actor Dolph Lungren, who guest starred in the special.
Snoop Dog was featured in an episode at one point.