Depends. Most people have different tastes when it comes to age and looks. Some people might find a 70-year-old guy handsome whereas some will find him unappealing.
For me, aesthetic retention is the biggest factor. If a dude or a gal retains most of their attractive features throughout aging, they'll still be appealing, without much need for plastic surgery. Try Diane Lane, Jennifer Aniston, David Carradine and George Clooney.
Most Filipinos know this, but some of our old 40+ actors still look like handsome leading men and suave dudes, most naturally retaining their facial attractiveness in aging.