Sizzler is a restaurant chain mostly located in the Western United States. A separate, non-affiliated chain known as Sizzler International operates internationally out of Australia.
Peter tries to pick up a girl in "Peter's Got Woods" by noting that he has a coupon for Sizzler.
Brian tells Tom Tucker in "Short Cuts" that his newly-achieved brush with fame include some perks, including presiding over the opening of a Sizzler that morning. Although he refuses to eat there, he does read a card that notes that they have 'the worst version of your favorite meal.'