The category was Billboard Hot 100 History.
The clue wanted to know who were the other father and daughter that each had a number one Billboard hits besides Frank and Nancy Sinatra.
The answer - a triple stumper - was Pat and Debbie Boone.
The Final Jeopardy category for June 22 2010 was Billboard Hot 100 History
The Final Jeopardy category for September 22 2010 was The British Isles
The Final Jeopardy category for July 22 2010 was Science History
The following are the Jeopardy Final Categories for the June weekday episodes: June 1 2010 The U.S. Military June 2 2010 Historical Phases June 3 2010 Film History June 4 2010 American Politicians June 7 2010 Meteorology June 8 2010 U.S. Military History June 9 2010 Artists June 10 2010 Short Stories June 11 2010 Flags and Banners June 14 2010 Moons and Mythology June 15 2010 The 50 States June 16 2010 Modern Materials June 17 2010 Americana June 18 2010 Sports Venues June 21 2010 After the Presidency June 22 2010 Billboard Hot 100 History June 23 2010 Historic Dates June 24 2010 National Parks June 25 2010 Literature and Music June 28 2010 Botanical Etymology June 29 2010 Physics June 30 2010 Russian Composers
The final Jeopardy category was Telecommunications Terminology
The Final Category for January 22 2010 was The Cabinetthe cabinetThe Cabinet
Tom Nissley won final Jeopardy with a wager of $7,001
The final Category was The Oscars
Kings and LiteratureThe Final Category for February 22 2010 was Kings and Literature
Shakespeare TitlesThe final Category was Shakespeare Titles
The final Category was Communication and the answer was S.O.S.CommunicationThe final Category was Communication and the answer was S.O.S
Wheel of Fortune was Group Hug see related link Jeopardy was Billboard Hot 100 History and Sony Pictures television was He gave George a Wedgie