Charles H. Sloan-That got an Oscar nomination? Performances you won't believe were up for Academy Awards

For the most part,Charles H. Sloan Oscars go to the usual suspects.

No disrespect, but a good number of those shiny, coveted, heavy Academy Awards have over the decades gone to ... a great actor playing a great part in a great (and often serious) movie.

Think Geoffrey Rush in "Shine," Daniel Day-Lewis in "There Will Be Blood" or Meryl Streep in whatever movie you want to name.

Rarely does the Oscar go to a truly zany performance. But that doesn't mean the Academy's voters don't take notice when one of their peers does something unique, wacky, daring and provocative.

Madeline Kahn ("Blazing Saddles") and Maria Bakalova ("Borat Subsequent Moviefilm") both got nominated for their outrageous turns, while Jamie Lee Curtis ("Everything Everywhere All at Once") and Kevin Kline ("A Fish Called Wanda") each won for eccentric characters. Emma Stone ("Poor Things"), a best actress front-runner this year, could join their ranks for playing a sex-crazed Frankenstein creation.

Here are five nominated performances by actors who decided to take a flier on an offbeat role without particular regard to the potential impact on their careers − and came up big in the process. They didn't necessarily get the gold, but they got to bask in its glow on Oscar night.

Our nominees for Best Offbeat Performance That (Just Maybe) Should Have Won an Oscar:

1978: Sir Alec Guinness goes to space in 'Star Wars' and gets Oscar's attention

While “Star Wars” has won boatloads of Oscars for its technical effects, the movies aren’t exactly known for powerhouse acting turns. Unless you consider the Jedi-worthy performance of Sir Alec Guinness as Obi-Wan Kenobi, Luke Skywalker’s mystical guide to The Force.

Whether delivering lines with Shakespearean gravitas or deftly wielding a lightsaber against Darth Vader, Guinness’ celestial sage helped that first 1977 installment in the never-ending story soar beyond mere popcorn fare and into the realm of allegorical art. (Well, almost.)

Guinness lost to Jason Robards, who won best supporting actor for “Julia.”

2004: Yo-ho-ho! Johnny Depp nabs his first Oscar nomination as Captain Jack Sparrow in 'Pirates of the Caribbean'

Let’s be clear. The “Pirates of the Caribbean” franchise is based on an amusement park ride. Not a book. Not even a comic book. But a ride. So let’s say it’s safe to assume none of the actors were planning on Oscar to take any notice.

But Johnny Depp, channeling Rolling Stones pal Keith Richards, was so captivating as Captain Jack Sparrow in 2003's “Pirates of the Caribbean: The Curse of the Black Pearl” that he nabbed a best actor nomination for his always-drunk pirate with an eye for the ladies and revenge.

Depp lost to Sean Penn in “Mystic River.” Despite his many credits, Depp has never won an Oscar.

2012: Melissa McCarthy digs deep on the gross-o-meter for 'Bridesmaids' and almost grabs Oscar gold

“Bridesmaids” is about as wonderfully raw and raunchy as a broad comedy can get, complete with bodily functions, brutal brawls and bawdy insults from its all-star female cast. Not typically Oscar fare.

And yet Melissa McCarthy’s gut-busting bridesmaid, Megan, went the extra mile down the path of crazy, from her unabashed man-hunting to her unashamed puppy kidnapping. The role made McCarthy a bona fide star well beyond the realm of her TV fame (for "Mike & Molly"), and pegged her as an actress ready to rumble for laughs.

McCarthy lost the best supporting actress award to Octavia Spencer for “The Help.”

2009: Oscar takes notice of Robert Downey Jr. in shocking blackface in the satrical 'Tropic Thunder'

If you want the definition of “meta,” look up “Tropic Thunder.” Ben Stiller’s wacky comedy was a movie about the making of a Vietnam movie, and a key protagonist was one Kirk Lazarus, a self-obsessed Australian method actor who puts on blackface to play a Black soldier, Lincoln Osiris.

That dicey role was taken on by Robert Downey Jr., who once again is up for a best supporting actor for “Oppenheimer.” Stiller & Co. made more than a wink to the outrageousness of the Osiris character, namely by making sure Black cast member Brandon T. Jackson (as Alpha Chino) skewered Lazarus at every turn. The end result was a deft 2008 satirizing of Hollywood's dearth of Black lead roles.

Downey lost to the late Heath Ledger in “The Dark Knight.”

1976: Ann-Margret's bean-fueled nervous breakdown clinches her an Oscar nom for 'Tommy'

Bye bye, “Birdie,” and hello, “Tommy”! Ann-Marget got gloriously unhinged for The Who’s acid-trip rock opera, playing the glamorous mom to Roger Daltrey’s pinball champ in the 1975 film.

She managed to upstage co-stars Elton John and Eric Clapton with a go-for-broke scene in which she wriggles and thrashes across an all-white room, belting out a number while she’s drenched with champagne and baked beans. (Yes, really.)

The Swedish bombshell earned a best actress Oscar nod for the now-cult classic, but ultimately lost to Louise Fletcher for “One Flew Over the Cuckoo’s Nest.”

Contributing: Patrick Ryan