Hal Rubenstein's Oscar Fashions

Who won, and more importantly, what were they wearing?

Every year InStyle magazine's fashion director, Hal Rubenstein joins ABCNEWS' Good Morning America the day after Hollywood's biggest party to give us the low down on the best and the worst of the beads and bodices.

"Expectations were really, really high this time because there were over a dozen of Hollywood's prettiest, youngest, and just everyone in fashion, everyone in movies was waiting to see how this parade was going to go," Rubenstein said.

This year makeup and hair really captured the biggest stars' overall looks, more than their designer frocks. Some celebrities went with a romantic look, while others opted for "big hair," and some didn't bother at all.

"Despite fashion mags decreeing flat, straight hair the thing, Jennifer Lopez wasn't having it. She was going big '80s. Gwyneth Paltrow went with the 1880s, and Cameron Diaz, well, she just canceled her appointment," Rubenstein said.

Rubenstein didn't dig Diaz's do — and her dress didn't win any praise from him either. "I don't know, this girl's got something against award shows. She's fighting this thing tooth and nail."

Gwyneth Revealed

But Diaz wasn't the worst dressed, Rubenstein reserved that position, with reservation, for a Best Actress winner from Oscars past.

"It just kills me to say Gwyneth Paltrow because she's just so radiant, beautiful," Rubenstein said. "She's done so much to help fashion and movies, but last night she just made a mistake." Paltrow's make-up was applied with a heavy hand, but she could have used a bit of cover-up a few inches lower. Her sheer Christian Lacroix tank dress in steel gray showed off a lot, without much support.

Who looked just perfect in Rubenstein's eyes? A young Hollywood actress, with very little experience on the red carpet. "Eat with a spoon, delicious from head to toe, Reese Witherspoon (pictured at top of story) is giving Hollywood a fresh definition in poise and style," Rubenstein said. Witherspoon, who appeared in Legally Blonde last year — not an Oscar-nominated film — wore a black cap sleeve dress with black lace trimming at the bottom.

Where's J.Lo?

Jennifer "J.Lo" Lopez usually produces gasps in the crowed with her risqué picks, but this year she opted for a traditional look. Rubenstien "loved" her dress, a simple fitted strapless Versace, but he thought Witherspoon's overall look shined a bit brighter.

Rubenstein was impressed by Halle Berry's overall look, but he didn't love her sheer-topped dress with strategically placed flowers. She won Best Actress anyway. Julia Roberts got high marks in a yet another classy black dress — a Giorgio Armani gown full of cut-outs. Jennifer Connelly won for Best Supporting Actress, but Rubenstein didn't think her champagne-colored strapless gown with a tiered skirt by Balenciaga fit her big moment. "Winners should cascade in tears, not tatters, he said."