The Oscars is a pivotal moment in an actor's or actresses' career. It is the most-coveted award in a business littered with competition and hurdles. The Oscars represents that crowning moment of glory, making it all the exhausting auctions, 18-hour filming days and scathing reviews worth it. Winning an Academy Awards solidifies one's position in Hollywood history.

The 2012 Oscar nominations were announced Tuesday morning. Top contenders include The Artist, Girl with the Dragon Tattoo, The Iron Lady and The Descendants. Famous faces like George Clooney, Rooney Mara, Angelina Jolie, Brad Pitt, Steven Spielberg and more will be in attendance.

Not only is the Academy Awards a glorious celebration of art, it is a celebration of fashion.

Each year actresses step out in the most stunning ensembles created by some of the world's most renowned designers. Hollywood is so revered for its magic. The fashions on the carpet echo that fantastical nuance.

And dressing for the Oscars is no small feat.

If you want a custom gown sketched by a designer with beading and embroidery, that can take many weeks to prepare, Marilyn Heston, head of MHA, an LA-based international company that pairs celebrities with designers and luxury brands, told The Hollywood Reporter.

It's not an overnight deal to get a spectacular Oscar dress. Generally, these tailor-made dresses are only offered to nominees and presenters for the Globes and the Oscars. If a designer spends all that time and money on a gown, they want to make sure that it will end up in Vogue or Women's Wear Daily. This is not an artistic endeavor. The only reason a global designer is dressing an actress is to gain exposure that will raise awareness and increase sales.

Take a look back at the best Oscar dresses of all time. Which gown is your favorite?