Perhaps it's starting to cool off in your neck of the woods, but in Hollywood the red carpet arrivals are hotter than ever in the fall. Click on to see which stars sizzled in September and October, and who fizzled.

Photo by Steve Granitz, WireImageMegan Fox
Jennifer's Body press event in LA
Grade: A

The sexy siren rocked a ruffled dusty rose Antonio Berardi dress, gold Brian Atwood pumps, and a Judith Leiber clutch at the Hot Topic-sponsored soiree.

Photo by Jon Kopaloff, Film MagicJennifer Aniston
Love Happens LA premiere
Grade: A+

The former "Friend" put women nearly half her age to shame (yes, that includes Megan Fox) in a tantalizing Valentino Couture tunic and bejeweled Christian Louboutin stilettos at the LA premiere of her latest romantic drama.

Photo by Jon Kopaloff, Film MagicJuliette Lewis
Whip It! LA premiere
Grade: F

The rock chick looked absolutely ridiculous at the premiere of Drew Barrymore's directorial debut in a sparkly trash bag, swirly stockings, and lace-adorned hot pink gloves.

Photo by Stefanie Keenan, WireImageRenee Zellweger
2009 Women in Hollywood Tribute
Grade: B+

Renee attended the 16th Annual Elle Women in Hollywood Tribute -- sans rumored beau Bradley Cooper -- in a fabulously fiery Carolina Herrera frock and a perfect pair of black pumps.

Photo by Mike Coppola, Film MagicPenn Badgley
The Stepfather New York premiere
Grade: B+

The "Gossip Girl" hunk got gussied up in a gray wool suit, black accents, and that signature smile of his for the premiere of his trashy thriller.

Photo by Dimitrios Kambouris, WireImageTaylor Momsen
The Stepfather New York premiere
Grade: D-

Penn's TV co-star continued to embarrass herself in yet another goth getup consisting of a lace minidress, patterned tights, and raccoon-like eye makeup.

Photo by Jemal Countess, Getty ImagesLauren Ambrose
Where the Wild Things Are New York premiere
Grade: B

The former "Six Feet Under" star was cute as can be in an off-the-shoulder cocktail frock, which she paired with nude peep-toes and a purple python clutch.

Photo by Jon Kopaloff, Film MagicEmily Blunt
2009 Women in Hollywood Tribute
Grade: A

The English actress popped a pose in a $2,800 tulle bow-enhanced Dolce & Gabbana dress, minimal makeup, and complimentary accessories.

Photo by Jeffrey Mayer, WireImageJaime King
2009 Scream Awards
Grade: F

Not only was Jaime King's Marc Jacobs asymmetrical tiered mini dress a hot mess, her heavy makeup and monstrous hairdon't were also huge mistakes.

Photo by Steve Granitz, WireImageJennifer Garner
The Invention of Lying LA premiere
Grade: C

Jen's highlights and sideswept bangs were kinda hot, but her 2010 Gucci Resort mini and boring satin heels were kinda not.

Photo by Steve Granitz, WireImageKristen Bell
Couples Retreat LA premiere
Grade: A-

The blond bombshell was the belle of the ball in a strapless Marchesa frock with stunning chiffon detailing, which she paired with a simple diamond tennis bracelet, satin Louboutin peep-toes, and a loose updo.

Photo by John Shearer, WireImageMalin Akerman
Couples Retreat LA premiere
Grade: B+

Also in attendance ... Malin Akerman, who gave Kristen a run for her money in a yummy yellow bustier, ruched nude skirt, and Miriam Haskell pearl-encrusted cuff.

Photo by Michael Tran, Film MagicElizabeth Banks
Surrogates LA premiere
Grade: F

Ms. Banks failed thanks to her boring Farah Angsana Fall 2009 frock, unflattering bow-accented heels, and messy mane.

Photo by Alberto E. Rodriguez, Getty ImagesMaggie Q
The September Issue LA premiere
Grade: A-

The model-turned-actress' $1,900 dusty pink Azzaro dress and nude Brian Atwood pumps impressed everyone, including the star of the film, American Vogue editor-in-chief Anna Wintour.

Photo by Stefanie Keenan, WireImageKatie Holmes
2009 Women in Hollywood Tribute
Grade: B+

Tom Cruise's trusty sidekick looked better than she has in quite some time in a sexy sheer Azzadine Alaia ensemble and softened 'do.

Julianne Moore
"Chloe" London premiere
Grade: A-

The insanely talented big screen star worked the arrivals line in a stunning strapless Bottega Veneta Resort 2010 gown and her iconic head of red.

Photo by Jon Kopaloff, Film MagicDrew Barrymore
Whip It! LA premiere
Grade: C+

The first-time director truly disappointed at her big premiere in a snooze-inducing L'Wren Scott black fitted dress, mismatched heels, and greasy mane.

Photo by Steve Granitz, WireImageViola Davis
Law Abiding Citizen LA premiere
Grade: A-

Viola stole the spotlight at a SoCal screening of the action flick in a bright-as-can-be beauty and cute new coif.

Photo by Jemal Countess, Getty ImagesBlake Lively
Where the Wild Things Are New York premiere
Grade: A+

Blake wowed upon arriving at the highly-anticipated premiere by wearing a magnificent Marchesa dress, which featured a black feathered skirt and an embroidered floral bodice.

Photo by Jon Kopaloff, Film MagicBai Ling
Zombieland LA premiere
Grade: B+

Truth be told, the Z-list "actress"/tabloid train wreck looked better than ever in an electric blue ball gown which featured a flowing train.

Photo by Jon Kopaloff, Film MagicKate Beckinsale
Whiteout LA premiere
Grade: A

Despite the fact that "Whiteout" bombed at the box office, Kate Beckinsale took our breath away at the thriller's LA premiere in a simple yet stunning Jill Sander gown, gold accessories, and unruly 'do.

Photo by Gaye Gerard, WireImageVince Vaughn
Couples Retreat Sydney premiere
Grade: D-

Schlubby. 'nuff said.

Photo by David Livingston, Getty ImagesCarey Mulligan
An Education LA premiere
Grade: B

The pint-sized star and soon-to-be Oscar nominee put her best foot forward in a strapless floral Lanvin frock and $1,100 studded Louboutin heels.

Photo by Jon Kopaloff, Film MagicAmber Heard
Zombieland LA premiere
Grade: A

The starlet nearly set off the sprinkler system in a white hot Paule Ka mini and Dior Couture Spring '08 wedges.

Photo by Jason Merritt, Film MagicRumer Willis
Sorority Row LA premiere
Grade: B+

The budding screen star suited up nicely in a Stella McCartney ensemble for the debut of her box office bomb.

Photo by Frederick M. Brown, Getty ImagesEve
Whip It! LA premiere
Grade: D-

Hopefully the rapper-turned-actress burned her burgundy bustier-enhanced Dolce & Gabbana dud post premiere.

Photo by Jim Spellman, WireImageCatherine Keener
Where the Wild Things Are New York premiere
Grade: B+

Thanks to her age-appropriate ensemble, featuring a classy jade jacket, the leading lady easily earned herself a B+.

Photo by Carlos Alvarez, Getty ImagesNaomi Watts
57th San Sebastian Film Festival
Grade: F

The Oscar nominee channeled MC Hammer upon arriving at the star-studded fete in a silly Stella McCartney jumpsuit, complete with a yucky lace yoke.

Photo by Jordan Strauss, WireImageAudrey Tautou
Coco Before Chanel LA premiere
Grade: B

The "Coco Before Chanel" star kept is simple yet chic in a Lanvin Fall 2009 LBD, patent leather belt, and super cute hair accessory.

Photo by Jordan Strauss, WireImageKherington Payne
Fame LA premiere
Grade: B+

The modern dance diva dressed to impress in a daring Christian Cota creation and strappy Stuart Weitzman heels.