James Marsden
James Marsden from movies like X-Men and 21 Dresses might be getting close to fifty, but he still could easily pass for someone in their twenties. This ageless heartthrob has been able to stop time and hold on tightly to his youthful looks. Maybe it has something to do with the mutant genes.
I would say it is a definite possibility considering the rest of the cast seems to have to stop aging as well. I have never wanted to be a mutant so much in my life. I wonder just how many of them will end up on this list. We will see if he makes the list again in another twenty years.