Michael Bublé -- Good Genes or Good Docs?

Michael Bublé's good looks are all we want this holiday season!

Here's a 28-year-old version of the singer that keeps the Christmas spirit alive at a signing in New York City back in 2003 (left) and 15 years later ... The now 43-year-old was showing off his winter scruff earlier this month in Germany (right).

Feeling good!

The question is ...