Fouquet in "The Man In The Iron Mask" is my third favorite TV character played by Patrick McGoohan - as long as 'The Prisoner' and John Drake the 'Danger Man' are considered the same character.
So here's a quickie Super Six list:
1] John Drake/Number Six, 'Danger Man', 'Secret Agent', 'The Prisoner'
2] Nelson Brenner, 'Columbo' - "Identity Crisis" (who is also Curtis from 'The Prisoner' - "Schizoid Man"
3] Fouquet, "The Man In The Iron Mask"
4] Reverend Syn, 'The Scarecrow Of Romney Marsh'
5] Colonel Lyle C. Rumford, 'Columbo' - "By Dawn's Early Light"
6] Oliver Quayle, 'Murder, She Wrote' - "Witness For The Defense"