Griffin is one of the newer and most appealing of the two-syllable Celtic surnames. In English, griffin is the name of a mythological creature, half eagle, half lion. It entered the list in 1983 after an absence of 75+ years, and has been climbing ever since, now at Number 241.
Brendan Fraser, Teri Polo and Joey McIntyre all chose Griffin for their sons. Actor Griffin Dunne's mother's maiden name was Griffin. Another well-known bearer was Griffin Bell, Jimmy Carter's Attorney General.
Also worth considering: the original classic Welsh Gruffudd (dd=th).