Cameron Diaz -- Good Genes Or Good Docs?!

Cameron Diaz's looks over the years are so Holi-bae!

Here is a stunning 34-year-old version of the blonde bombshell actress looking camera-ready in Surrey, England, playing the hot L.A. movie trailer producer -- who is incapable of crying in the classic holiday film -- "The Holiday" back in 2006 (left).

And, 17 years later the hot momma and blue-eyed beauty recently sat down with Jimmy Fallon and graced America by flashing her pearly whites and a festive lip on 'The Tonight Show' (right).

Her million-dollar smile continues to shine bright, and she will forever be a holiday fave!

The question is ...