8 Oscar winners who totally lost it during their acceptance speeches

The Academy Awards celebrate actors for their work on film, but sometimes their most emotional performances take place on the Oscar stage.

After all, Hollywood's biggest night is often where the dreams of many stars become a reality, and with that, a lot of tears. Here are some of the most sob-filled Oscar moments in recent memory.

WATCH: Every Time Leonardo DiCaprio Lost at the Oscars, but Handled It With Class

1. Nicole Kidman: Best Actress, The Hours (2003)

Despite a valiant fight to hold back the tears, Kidman couldn't stop the waterworks from flowing.

"Russell Crowe said, 'Don't cry if you get up there,' and now I'm crying," she said.

2. Natalie Portman: Best Actress, Black Swan (2011)

Portman couldn't have been more grateful to take home the award, but she admitted that an even better prize would have been to work with her fellow nominees Nicole Kidman, Jennifer Lawrence, Annette Bening and Michelle Williams.

"I'm so in awe of you," she said.

3. Ben Affleck: Best Picture, Argo (2013)

Academy of Motion Picture Arts and Sciences

In one of the fastest Oscar speeches ever given, Affleck sped through the names of those he had to thank, but slowed down to reminisce about his first Oscar win that took place more than a decade prior.

"I had no idea what I was doing," Affleck said, referring to his Best Original Screenplay win with Matt Damon in 1998 for Good Will Hunting. "I stood out here in front of you all, really just a kid. I went out and never thought I'd be back here, and I am because of so many of you who are here tonight."

(You can watch the speech here.)

4. Jennifer Hudson: Best Supporting Actress, Dreamgirls (2007)

"I didn't think I was going to win," Hudson admitted, holding her statuette.

The former American Idol hopeful went on to pay homage to her late grandmother, who was her inspiration for pursuing a showbiz career.

5. Octavia Spencer: Best Supporting Actress, The Help (2012)

Spencer's emotional speech brought the entire room to their feet, but she also got a big laugh with her opening line.

"Thank you, Academy, for putting me with the hottest guy in the room," she joked.

6. Charlize Theron: Best Actress, Monster (2004)

Theron started out cheerful but began to get teary-eyed when thanking her home country of South Africa. By the time she started talking about her mother, Gerda, she was a goner.

"You have sacrificed so much for me to be able to live here and make my dreams come true," she said. "There are no words to describe how much I love you."

7. Gwyneth Paltrow: Best Actress, Shakespeare in Love (1999)

Paltrow basically cried from start to finish during her acceptance speech, which quickly became one of the most memorable moments in the awards show's history. When it came time to thank her family, the actress nearly broke down completely.

"I would not have been able to play this role had I not understood love of a tremendous magnitude and for that I thank my family," she said.

8. Halle Berry: Best Actress, Monster's Ball (2002)

There wasn't a dry eye left in the house when Berry climbed the stage, already sobbing, and became the first African-American actress to claim the prestigious honor.

Bonus Cry -- David Oyelowo: Selma (2015)

While Oyelowo didn't win an award himself, he was overcome with emotion by watching Common and John Legend accept their Best Original Song Oscars for "Glory" from the movie, Selma, in which Oyelowo portrayed Martin Luther King Jr.

"This moment is so much bigger than me," she said in her speech. "This moment is for Dorothy Dandridge, Lena Horne, Diahann Carroll. It's for the women that stand beside me: Jada Pinkett, Angela Bassett, Vivica Fox. And it's for every nameless, faceless woman of color that now has a chance, because the door tonight has been opened."

Don't miss ET's live Academy Awards pre-show on Pop this Sunday, Feb. 28, starting at 5 p.m. ET/2 p.m. PT. Go to PopTV.com to find out where to watch.