Jennifer Aniston and Cate Blanchett, 42
Cate's fair skin and mature roles make her seem older than Jen, who will forever look like she's 34. (AP)
Madonna and Melanie Griffith, 53
The Material Girl has recently done something to her face that makes her look older than Melanie - who is also a fan of plastic surgery. But for the most part we think of both of these ladies as young at heart. (REUTERS)
Teri Hatcher and Calista Flockhart, 46
While Teri Hatcher (left) was prancing around in lingerie on the set of "Desperate Housewives," Calista (right) was playing a far more dramatic role on "Brothers & Sisters." (AP)
Anna Kendrick and Florence Welch, 25
The lead singer of Florence and the Machine (right) has a soulful voice and an old Hollywood look that make it hard to believe she's only 25! Anna Kendrick (left) is true to her age - even though she plays a high school student in the "Twilight" saga. (AP/REUTERS)
Whitney Houston and Felicity Huffman, 48
Everyone knows what happens when you don't take care of yourself. Whitney (left) looks remarkably good considering her lifestyle choices. Felicity (right) is an example of how good 48 can really look. (AP/REUTERS)
Salma Hayek and Lauren Graham, 44
The Mexican star (right) is married to Francois-Henri Pinault, 49, who looks like he could be 20 years her senior. Can someone look old by association? The "Parenthood" star (left) just always seems like the young mom on "Gilmore Girls". (AP/REUTERS)
Kate Winslet and Isla Fisher, 35
The Oscar winner (left) seems like she has an old soul. We're not sure if it's the roles she chooses or the dresses she wears, but she seems much older than Isla Fisher (right). (AP)
Toni Collette and Sofia Vergara, 38
What? Sofia Vergara (right) is close to 40?! While that is very hard to believe, we thought Toni (left) celebrated her 40th years ago. (AP/REUTERS)
Patrick Dempsey and Charlie Sheen, 45
Charlie's (left) wild lifestyle has added countless years to his face. The "Grey's Anatomy" star (right). (REUTERS)
Rene Russo and Meredith Vieira, 57
Meredith Vieira the "Today" (left) host and Rene Russo (right) (AP/REUTERS)
Katherine Hiegl and Rachel McAdams, 32
“The Notebook” star (right) seems way more young and playful than the mature looking “Killers” star (left). (AP/REUTERS)
Catherine Zeta-Jones and Gwen Stefani, 41
It's hard to believe that the always fashionable, midriff-baring No Doubt singer (right) is already in her 40s. However for Catherine, it's quite believable. (REUTERS)
Angelina Jolie and Reese Witherspoon, 35
This one's a shocker. The southern darling (left) seems like she's barely hit her late 20s. While Angelina Jolie (right) could easily have celebrated her 40th birthday by now. (REUTERS)
Sarah Jessica Parker and Sandra Bullock, 46
The "Sex and the City" star (left) seems older since she's been on HBO since 1998. Sandra Bullock's (right) career didn't really kick into high gear until "Miss Congeniality" in 2000. Plus, Sandra is a relatively new mom while SJP has an eight-year-old with her husband of 13 years Matthew Broderick. (AP/REUTERS)