Are you asking relative to admissions chances or relative to achieving "success" in your life? French is the the language of international law e.g. one of the languages that is spoken at the Haugue; but that Gaelic Irish stuff has a lot of practical uses too, especially after you get into KP and if you find yourself at McSorley's Pub in downtown Manhattan for the St. Patty's Day Parade....
As far as admissions, anything Foriegn Languages included that demonstrates you are a well rounded successful student is generally helpful.