"I'm pregnant, McGee. Twins. Haven't told the father yet. It's Gibbs. I know it's wrong, but something about his silver hair gets me all tingly inside."
—Abby Sciuto, NCIS
Age is all in the mind.
But then, there are those who get better as they age; the ones who still qualify for the 'desirable' tag, even when they're grandparents. These men and women have maintained their dashing good looks, class, and sex appeal despite - or because of - their greying hair.
They become a Silver Fox.
A Silver Fox is an attractive, distinguished older (generally over 40) person, often noted for his or her sexy silver or white-hair along with their good looks and charm.
Anime and Manga
- Ishida Ryuuken from Bleach is probably about 40 and his hair has gone completely white, but he's as strikingly pretty as (and almost as slender as) his teenage son Uryuu. Although given his name and his stern personality, he's really more of a Silver Dragon.
- Joseph Joestar during the "Stardust Crusaders" arc. This is set a few years after fathering Josuke, making his son younger than his grandson, Jotaro.
- Sisterhood series by Fern Michaels: Free Fall introduces a defense attorney named Elizabeth "Lizzie" Fox, who is at least 30 years old and has completely silver hair. It will probably not come as a surprise that she's been given the nickname "The Silver Fox"!
- Borderline between this and White-Haired Pretty Boy, but when Akhor the Silver King of the Kantri becomes human, he has long silver hair. His age then is indeterminate, but his eyes show something of his thousand-year life. His Love Interest is all over him in this form, and he's all over her; otherwise people don't note if he's attractive... except that one human friend of his who gets hugged notes in the narration that she can't help but notice that he smells amazing.
- The Third Doctor from Doctor Who. True, One could be very charming when he wanted to be, but he still looked every day of William Hartnell's age at the time. Patrick Troughton as Two was far from ugly and had his charms, but he wasn't gorgeous either. However, Jon Pertwee as Three managed to be an old guy with a very snappy sense of style (both in fashion and demeanor), looked and acted very fit for his age, and generally made being a Badass Grandpa look good.
- Gibbs from NCIS.
Abby: I'm pregnant, McGee. Twins. Haven't told the father yet. It's Gibbs. I know it's wrong, but something about his silver hair gets me all tingly inside.
- Tony's father also qualifies.
- And Jamie Lee Curtis's character Dr. Samantha Ryan, from Season 10. Yowza.
- Gil Grissom, CSI. Even his future wife, Sara, drops a line about finding grey hair sexy, while he's in the room, no less.
- DI Lestrade from Sherlock.
- Roger Sterling from Mad Men.
- Metal Gear: Big Boss, Old Snake, The Sorrow, and Big Mama (older EVA) all can count as this.
- Sun Jian, starting from Dynasty Warriors 6 on.
- It helps that, historically, he only lived to be 36.
- Ezio in Assassin's Creed: Revelations. He's 53 and still running around preforming rooftop acrobatics and charming his new love interest, who's almost 20 years younger than he is.
- General Tarquin from Order of the Stick. Haley sees him as evidence that his son, Elan, is still going to be attractive in his middle age. Although, here, it is Informed Attractiveness, since it's a Stick Figure Comic.
- Dora of Questionable Content squees upon meeting Marten's father with his full head of grey hair, saying that Marten will look so hot when he gets old.
- Anderson Cooper. Just Anderson Cooper. Notable for the fact that he went completely gray at a rather young age.
- There's no debating the fact that George Clooney is sexier now than he was when he was in his 20s.
- Helen Mirren is every bit as sexy now as she was thirty years ago - if not sexier.
- The ultimate silver fox: Sean Connery.
- Dmitri Hvorostovsky, Russian baritone.
- Shaun Micallef is well-known for being a silver fox, much to the TV host's bemusement.
Micallef: "Silver fox? Is that good?"
- Tony Jones from ABC1's Q and A and Lateline is actually called the "Silver Fox" on many a Monday night by the Twittersphere. 
- Surely, Hugh Laurie counts as one.
- David Byrne of the Talking Heads.
- Steve Martin, anyone?
- John Slattery, so [dead link] much [dead link]. It helps that he's prematurely gray, making him substantially Younger Than He Looks. (He was born in 1962.)
- Janove Ottesen, charismatic frontman of Kaizers Orchestra, seems to be heading this way. Not even 40 yet, but he's already proudly rocking the grey-haired look.
- Alan Rickman, definitely.
- Richard Gere.
- Robert Wagner
- Tim Gunn. Named one of People Magazine's "Sexiest Men Alive" in 2006.
- Jamie Lee Curtis; especially notable is that she's become quite a vocal opponent of Photoshopping and other forms of photo retouching, and manages to look damn good with only a pixie cut and a little bit of makeup.
- Geoffrey Zakarian.
- Some men's hair dyes are designed to cover up some, but not all, of their gray hairs, so as to give them a dignified salt-and-pepper look while still remaining somewhat youthful.