Here's a list of states where one party controls both Senate seats and how long it has been since a member of the other party held a seat:
30+ years
Kansas: George McGill (1939!)
West Virginia: William Rivercomb (1959)
New Jersey: Clifford Case (1972)*
20-30 years
Hawaii: Hiram Fong (THE ONLY R) (1977)
Wyoming: Gale McGee (1977)
Utah: Frank Moss (1977)
Massachusetts: William Brooke (1979)
New Hampshire: John Durkin (1980)
Idaho: Frank Church (1981)
Alaska: Mike Gravel (1981)
10-20
Maryland: Charles Mathias (1987)
Connecticut: Lowell Weicker (1989)
Mississippi: Ed Stentis (1989)
California: John Seymour (1992)
Texas: Robert Gruger (1993)
Wisconsin: Robert Kasten (1993)
Maine: George Mitchell (1995)
Oklahoma: Dan Boren (1995)
Tennessee: James Sasser (1995)
Arizona: Dennis DeConcini (1995)
10< years
Alabama: Thomas Heflin (1997)
Kentucky: Wendell Ford (1999)
New York: Al D'Amato (1999)
Delaware: William Roth (2001)
Michigan: Spencer Abraham (2001)
Washington: Slade Gorton (2001)
Arkansas: Tim Hutchinson (2003)
Georgia: Zell Miller
(2005)
Illinois: Peter Fitzgerald (2005)
North Carolina: John Edwards (2005)
South Carolina: Fritz Hollings (2005)
Rhode Island: Lincoln Chafee (2007)
Montana: Conrad Burns (2007)
*chose to discard Brady b/c he wasn't elected and it makes a big difference on years
