Jim O'Heir is primarily known as the eternally shat-upon Jerry/Garry/Larry/Terry Gergich on Parks & Rec - but he's sneakily been popping in on TV shows for years and years before he got his big break as IRL Meg Griffin.
Jim O'Heir was the Adoption Agency employee who mixes up Chandler and Monica's files with those of another couple looking to adopt, which ends up screwing up their plans to adopt a child. DAMMIT, JERRY.
Hey - Jerry was on Single Female Lawyer (or Ally McBeal, but I prefer to live my life in references)! In the episode "Saving Santa," Jerry played a Santa Claus that was fired for being too fat, which - honestly - is a VERY Jerry problem to have.
Remember the truck driver that both helped Francis with his mother issues and forced him into wearing a ridiculous clown outfit in exchange for hitchhiking to Alaska? That was none other than Jim O'Heir, who for once got to be both wise AND the one doing the tormenting. GOOD JOB, JERRY!