"I feel extremely comfortable being dressed as Ugly Betty," says Ferrera, 23. "It's always nice at the end of the day to take the wig off and take my makeup off and just be myself. But I am more comfortable being Betty than being on a red carpet all glammed up."
YOU KNOW HER AS ... PAM BEESLY on The Office
The downside of being Pam: "Being dialed down didn't bother me until the first time I saw myself in high definition," says Fischer, 33. "I was shocked. You see every pore. I was like, 'Wow, maybe we do want a little more of the under-eye concealer next week.'"
MARY LYNN RAJSKUB
YOU KNOW HER AS ... CHLOE O'BRIAN on 24
The following takes place after playing a computer nerd week after week: "Being so plain on the show forced me to want to be more glam," says Rajskub, 35. "It's really fun to be a lady and go out. I used to be a six-minute kind of person. Now I'll get the curling iron out, put on lashes and play around with lip color."
YOU KNOW HER AS ... LANE KIM on Gilmore Girls
"'Wow, you look better in person!' I get that a lot from fans," says Agena, 33, who says she's way more easygoing than her character but not overly glam. "I'm pretty low-maintenance," she says. "My husband [musician Shin Kawasaki, 30] hates makeup."
YOU KNOW HER AS ... LIZ LEMON on 30 Rock
What's the main difference between Fey and her character? "Her boobs are a lot bigger than mine," jokes Fey, 36, who prides herself on how fast she can get out the door in the morning. "If I'm not benefiting from hair and makeup, it takes 15 minutes. I'm in the mom habit [daughter Alice is 19 months] of showering the night before and letting my hair dry naturally. Sometimes it's curly, and sometimes it's just Frankenstein—I'm out the door either way." On-set grooming, however, isn't quite so breezy. "It takes about an hour just for hair and makeup. It's weird how much thought goes into a look that's supposed to look like I didn't do very much."