[6] Valentine got his start in show business on the standup comedy stage.
After an appearance at the Montreal Comedy Festival, he left for Los Angeles.
Valentine appeared on the television show Men of a Certain Age, which was written and directed by Ray Romano; the program received critical acclaim.
Prior to Valentine's run on the series, he starred in his own half-hour special on Comedy Central and hosted The X Show on FX.
On the big screen, Valentine has appeared in Stuck on You and I Now Pronounce You Chuck and Larry.