Erskine Childers: The Riddle of the Sands
Joseph Conrad: The Secret Agent
John Buchan: the Richard Hannay novels
Eric Ambler: all novels
Alistair MacLean novels
Graham Greene: The Quiet American, Our Man in Havana, The Third Man
Len Deighton: the Harry Palmer novels
Len Deighton: the Bernard Samson novels
John Le Carre
Robert Ludlum
Tom Clancy
Ian Fleming
Charlie Higson: the Young Bond novels
The Avengers TV series
The Man From UNCLE TV series
Mission: Impossible TV series & movies
I-Spy TV series
Alias TV series
24 TV series
Secret Agent aka Danger Man TV series
The Prisoner TV series
Burn Notice TV series
Get Smart TV series
The Man in a Suitcase TV series
Spy Kids movies