Biggest Oscar snub?

The Oscars are known as much for it's glitz and glamor as it's snubs. Who can forget how Martin Scorsese did not win an Oscar until The Departed after his body of work suggested otherwise? Stanley Kubrick not winning one ever? Glenn Close losing out for Fatal Attraction to Moonstruck star Cher?
In the end the debate over biggest snub comes down to five categories: 1997 Best Picture, 2000 Best Actress, 1980 Best Picture, Best Director 1964 and 1972. For those who do not remember any of these, let me enlighten. In 1964, Stanley Kubrick(Dr. Strangelove) lost to Carol Reed(Oliver!) for Best Director. In 1972, Bob Fosse(Cabaret)beat out Francis Ford Coppola(The Godfather) for Best Director. In 1980, Raging Bull lost to Ordinary People for Best Picture. In 2000, Ellen Burstyn(Requiem For A Dream) lost to Julia Roberts(Erin Brockovich) for Best Actress. In 1997 L.A. Confidential lost out for the Best Picture to monster, king-of-the-world smash hit Titanic. My question: which of these is the worst oversight in the Academy's history?
The debate boils down between 1997 Best Picture and 2000 Best Actress. While Kubrick being shut out is an injustice, his loss came to excellent filmmaker. The same can be said for Francis Ford Coppola in 1972. Raging Bull losing in 1980 is a big snub, but it's loss wasn't to as inferior a movie as our 1997 loser.
In an acting category, no snub is more resounding than Ellen Burstyn losing to Julia Roberts in 2000. Julia Roberts has never been more than a charismatic actress, far from a character actor who has a broad range. Burstyn role in Requiem For A Dream is one of the most shocking, realized performances in cinematic history. She lost to Julia wearing a pushup bra. Ouch.

Yet when a little crime noire called L.A. Confidential lost Best Picture to Titanic, the greatest snub in the Academy's history went down. Yes, the Titanic that grossed one hundred gillion budabillion dollars and introduced us to love.......at 1000 leagues under the sea. Today, L.A. Confidential is considered to be one of the best films of the '90's and a classic. Titanic is still known as the movie that grossed one hundred zillion gigagigadillion dollares and introduced us to love, well you get the idea. Oh, and it confirmed to all that James Cameron was the king of the world. Well, all I know is that Jack and Rose wouldn't stand a chance versus Bud and Lynn. Mostly cause Bud is a hard boiled bad ass.

Every year the Academy prides itself on the quality of the categories. However, their occasional oversights can be as much of a story as the winners. At the end of the day, when the Academy gets one right, it's right, but when they make the wrong choice, it's embarrassing.