Which Best Actor/Best Actress Oscar (TM) of the past fifty years was the least deserving?

[Midwestern Democrat]

73. Burton seems to me to have been a victim of unfortunate timing but I do think O'Toole got robbed 2X

Here were his Best Actor nominations:

1954 - "The Robe" - Burton's not that great in this (was the weakest nominee) and the movie itself is a POS
1965 - "Becket" - a strong year (Peter Sellers in "Dr. Strangelove", Peter O'Toole in "Becket", and Anthony Quinn in "Zorba the Greek" ), but just like Yul Brynner in "The King and I", the Academy could not resist giving Rex Harrison the award for a beloved stage performance in "My Fair Lady"
1966 - "The Spy Who Came in From the Cold" - Lee Marvin winning for "Cat Balou" was a disgrace, but Rod Steiger deserved the award this year for "The Pawnbroker"
1967 - "Who's Afraid of Virginia Woolf?" - Paul Schofield was really good in "A Man for All Seasons"
1970 - "Anne of the Thousand Days" - an OK costume drama; John Wayne got the "Lifetime Achievement" Oscar, but Dustin Hoffman deserved the award this year for "Midnight Cowboy"
1978 - "Equus" - a weak year for Best Actor and I don't really like this film - it would not have been a bad thing for Burton to get a "Lifetime Achievement" Oscar for this role.

Peter O'Toole on the other hand, did get legitimately robbed at least twice (blatantly so in 1969):

1963 - "Lawrence of Arabia" - was robbed this year - it was the best performance nominated.
1965 - "Becket" - see above for Burton for this year
1969 - "The Lion in Winter" - he was blatantly robbed this year; Cliff Robertson's performance in "Charly" was quickly forgotten
1970 - "Goodbye Mr Chips" - see above for Burton for this year
1973 - "The Ruling Class" - no one was beating Marlon Brando for "The Godfather"
1981 - "The Stunt Man" - De Niro deserved his win for "Raging Bull"
1983 - "My Favorite Year" - very strong year - Ben Kingsley for "Ghandi"; Paul Newman for "The Verdict"; Dustin Hoffman for "Tootsie"; Jack Lemmon for "Missing"
2007 - "Venus" - didn't see this film nor the film Forrest Whitaker won for, so really can't comment