Possible Clues:

• Most-watched show of 2012-13
• Most-watched TV series of 2012-13
• TV drama set in the D.C. area
• America's favorite TV show, according to a 2015 Harris Poll
• Most-watched scripted US series since 2010
• Lead-in to 'Los Angeles' or 'New Orleans'
• Formerly top-rated show starring Mark Harmon
• 'JAG' spinoff starring Mark Harmon
• Police drama TV series where Mark Harmon investigates the military
• CBS show with two spinoffs