It's a big day for Neil Patrick Harris! The How I Met Your Mother alum is not only turning 41 today, but is also celebrating Father's Day, alongside longtime partner, David Burtka. Doting dad to son, Gideon, and daughter, Harper, the star has come a long way since his Doogie Howser days, swapping his doctor's coat for a well-tailored suit and tie a la Barney Stinson; and most recently, a pair of 4-inch heels and fishnets for his performance in Broadway's Hedwig and the Angry Inch, for which he recently won a Tony award. Harris has worn many hats throughout the years, but fatherhood may just be his favorite role. "The older they get, the more I love being a dad," the actor tells People. So sweet!