Season 1, "Model Clients"
Usually the models on Project Runway are fine with wearing whatever outfits the designers decide to put on them - but it was a different story on this episode, when Heidi announced the designers' challenge was to make the models' dream wedding gowns. Satisfying the models (especially the colorful Morgan) was no easy feat, but Kara Saun pulled out the win.

Season 1, "Postal Uniform Challenge"
Function and fashion were pitted against each other as contestants tried to design the perfect UPS uniform. Kara won with a chic messenger bag and aviator sunglasses, while Robert was auf'ed for an impractical, unattractive design.

Season 2, "Clothes Off Your Backs"
Heidi threw a rooftop celebration for the new batch of designers...then announced that their first challenge would be to make couture out of nothing but what they've worn to the party. While some designers went for broke, cutting up their beloved (and expensive!) leather jackets and jeans into exciting new looks, one contestant, Kristin, got the boot after refusing to part with an heirloom scarf that would have improved the tacky halter-and-skirt combo she made.

Season 2, "Window Shopping"
Contestants had to design not only a day-to-night piece for Banana Republic, but also a display window to show it off in. People on the street judging the designs and windows gave the win to Andrae and Daniel V. Less lucky: Diana and Marla, who were sent home because of a blah suit that was neither day nor night.

Season 2, "Flower Power"
Contestants smelled the roses with a trip to the New York Flower District to pick up material for their designs. Daniel V. wowed the judges with his use of color and texture, but Andrae's dress fell short of fabulous.

Season 3, "Wall to Wall"
In this challenge, contestants ripped up a furnished apartment in the name of fashion, incorporating everything from sofa leather to wicker baskets into their designs. The winner: Keith, whose bed-sheet dress featured cleverly placed duvet-cover buttons.

Season 3, "Designer's Best Friend"
Doin' it doggy style! In this memorable episode, contestants designed whimsical outfits for dogs and their owners. Uli's sophisticated patterned dress with jacket (and adorable pug accessory) took the win.

Season 3, "Waste Not, Want Not"
In a recycling-themed challenge, the designers dug through paper, plastic, rubber, and more to find material for their creations. Michael impressed the judges with an innovative dress and sash made out of plastic, while Alison's colored-paper dress got trashed by the judges.

Season 3, "Everyday Woman"
In one of the most tense episodes ever - remember the drama between Jeffrey and Angela's mom? -- contestants designed clothes for family members of other designers. Vincent won over the judges with his sleek dress for Uli's mom, and Robert got the boot for the shapeless black and red dress he made for Vincent's sister.

Season 4, "Fashion Giant"
A game-changing episode: In the first menswear challenge ever, the contestants were asked to design a three-piece suite for guest judge Tiki Barber. Jack scored a touchdown with a simple yet modern dress shirt and slacks. Carmen got auf'ed for designing a sloppy jacket with no shirt underneath.

Season 4, "Raw Talent"
Forget delicate and demure: In this challenge, the designers' clients were the butt-kicking babes of the WWE. Chris claimed victory with a skimpy leopard print for his wrestling all-star. Ricky bombed with a cheesy orange bathing suit.

Good Queen Fun
You probably suspected something was up when Season 4 Chris March paraded onto the runway dressed as a Viking woman with disco-ball err... yeah. The designers were dressing for drag queens, and the result was one of the more colorful shows in Runway history. Joe's pink sequined number was a hit - who predicted that the straight male designer would win the cross-dressing challenge?

Fashion That Drives You
Did you know that your old clunker could actually be used to create high-class fashion? Belts, buckles, seat cushions, covers, and air bags were just a few of the materials used when the designers had to create a look entirely out of spare car parts. Korto's seat belt woven jacket was a frontrunner, but it was Leanne's chic seat cover skirt and corset bodice that took the win.