Met Gala 2014 Fashion: Rihanna, Lea Michele Stun on the Red Carpet while Rita Ora and Katie Holmes Lead Worst Dressed List (SLIDESHOW)

Hollywood's A-list stars all flocked to New York City on Monday, May 5 for the annual Met Gala held at the Metropolitan Museum of Art. The Gala is known to be one of the most exclusive events in New York and usually boasts a guest list full of the biggest names in the entertainment industry.

On Monday stars like Beyoncé, Kim Kardashian and Gisele Bunchen graced the red carpet. Even a few Met Gala newbies made an appearance like actress Lupita Nyong'o, reality star and model Kendall Jenner and actress Gabrielle Union.

Before the Hollywood stars arrived, First Lady Michele Obama kicked things off with the ribbon cutting and unveiling of the Anna Wintour Costume Center at the Metropolitan Museum of Art. FLOTUS, dressed in a floral Naeem Khan gown, debuted the new $40 million center named after Vogue magazine's editor-in-chief.

According to the Latin Times, Wintour has raised over $125 million for the fashion wing of the museum.

"I'm so impressed by Anna's contributions not just to fashion but to this great museum. This center is for anyone who cares about fashion and how it impacts our culture and our history," Obama said during her speech.

The Anna Wintour Costume Center will open to the public next week and features an exhibit by Charles James. Now on to the best part of the entire evening: the red carpet fashion. Every year, the Met Gala provides a theme for celebrities to follow.

Last year, it was "PUNK: Chaos to Couture" but this year it was more formal and attendees were required to stick to a "white-tie" dress code.

Check out our list (and slideshow) of the stars that nailed the glamorous look and those that missed:

Best Dressed:

1. Rihanna in a white cropped Stella McCartney dress paired with Jacob & Co. and Dionea Orcini jewelry

2. Rosie Huntington-Whiteley in short Balmain dress that featured leather, gold and leopard print embellishments. She paired the look with giant hoop earrings and Balmain gladiator shoes.

3. Diane Kruger in a spaghetti strap ice blue dress by Hugo Boss with a matching satin belt and a pleated overlay.

4. Hailee Steinfeld in a black and white Prabal Gurung gown and nude satin shoes

5. Lea Michele in a silk gold Altuzarra gown with a plunging neckline and daring side slit.

Worst Dressed:

1. Karolina Kurkova in a tiered Marchesa gown with a floral design

2. Rita Ora in a gold, embellished Donna Karan Atelier dress with thigh-high strappy heels tied in the back

3. Nicole Richie also in a Donna Karan Atelier dress with sheer and velvet panels

4. Elizabeth Olsen in a short powder blue Miu Miu dress paired with a greenish blue clutch and colorful strappy heels

5. Katie Holmes in a floor-length mustard yellow Marchesa gown

Which stars did you think was the best and worst dressed of the evening?