Don Draper's been away for 17 months, but he's got nothing on Basil Fawlty
"The Sopranos" (21 months)
"The Sopranos": The longer the show stayed on the air, the longer the gaps between seasons became, as David Chase needed more time to come up with new stories, the actors took movie projects, and other complications got in the way. The biggest break came between the end of season 5 on June 6, 2004, and the start of season 6 on March 12, 2006. It was gone so long that actor Joseph Gannascoli, who played Family capo Vito Spatafore, lost 160 pounds during the hiatus, a development that was written into the new season, in which Vito felt emboldened by his weight loss and made a variety of bad decisions as a result.