Doogie Howser, M.D. teen star, and later was in How I Met You Mother.
He graduated high school with high honors after being heavily involved in the school's theater department.
He played himself in the Harold and Kumar movies.
He began dating David Burtka in 2004, and the couple had surrogate twins in 2010.
He is one of the main characters in How I Met Your Mother with Alyson Hannigan.