The show has been cancelled twice, once following the second season, which caused the show to not air a new episode for a year, and the second (and longest) being between the third and fourth seasons, from 2002 to 2005. The program was the first to be brought back to air due to successful home media sales.
Do you even know what sex IS?
Stewie Griffin: Now really I- don't change the- is it a kind of cake?
The final screen of end credits for each episode contains a standard disclaimer about all characters being fictitious. In the second season episodes, this is misspelled "ficticious".
Every few seasons, the instrumental version of the title theme that plays over the end credits is replaced with a new arrangement. To date there have been 5 main arrangements of the closing credits theme (this, of course, does not include "one-shot" versions that are relative to a specific episode.)
Versions of the show that air in syndication often have their commercial breaks in different places than the original network airings. This results in some rather jarring transitions that were not present in the original broadcasts, and commercials in strangely inappropriate places. One good example of this is that Peter introduced the cutaway about a secret place for his porn, then it went commercial, and the cutaway did not play until after the commercial break!