First stage role at age six, playing Toto in a school production of "The Wizard of Oz"
Met playwright Mark Medoff (scripted "Clara's Heart") at a drama camp at New Mexico State University
Feature debut starring opposite Whoopi Goldberg in "Clara's Heart"; received a Golden Globe nomination for Best Supporting Actor
Featured in the little-seen sci-fi comedy "Purple People Eater"
TV-movie debut in "Too Good to Be True" (NBC)
Breakthrough role as a child prodigy doctor on the ABC series "Doogie Howser, M.D."; earned a Golden Globe nomination for Best Actor
Voiced a young country mouse on the short-lived politically themed animated series "Capitol Critters"
Starred the NBC movie "A Family Torn Apart" as one of two adopted sons suspected of murdering their parents
Made professional stage debut starring role in "Luck, Pluck & Virtue"
Starred in the fact-based TV-movie "Snowbound: The Jim and Jennifer Stolpa Story" (CBS)
Featured in "Starship Troopers" as Colonel Carl Jenkins
Joined the Los Angeles production of the musical "Rent" as the narrator Mark
Starred as Romeo in San Diego production of "Romeo and Juliet"
Starred in the CBS holiday movie "The Christmas Wish"
Featured opposite Leelee Sobieski's "Joan of Arc" (CBS)
Critically praised for his turn as Tobias Ragg in the Los Angeles production of "Sweeney Todd"
Cast in NBC's "Stark Raving Mad" as a book editor assigned to work with an eccentric mystery writer
Featured in "The Next Best Thing" opposite Madonna and Rupert Everett
Recreated role of Tobias in a San Francisco production of "Sweeney Todd" (aired on PBS)
Joined the cast of Broadway's "Cabaret" in the role of the Emcee
Played a drug-crazed, lecherous parody of himself in "Harold & Kumar Go to White Castle"
Performed a dual role of the Balladeer and Lee Harvey Oswald on Broadway in Stephen Sondheim's "Assassins"
Cast as the womanizing Barney Stinson on the CBS comedy "How I Met Your Mother"
Once again played a parody of himself in "Harold & Kumar Escape from Guantanamo Bay"
Hosted the 63rd Annual Tony Awards at Radio City Music Hall
Hosted the 61st Primetime Emmy Awards on CBS
Voiced Steve the Monkey in "Cloudy with a Chance of Meatballs"
Appeared in "Cats & Dogs: The Revenge of Kitty Galore," the sequel to the 2001 family film "Cats & Dogs"
Guest starred as Bryan Ryan, a former high school show choir member on "Glee" (Fox)
Featured in the film "Beastly," a retelling of the fairytale <i>Beauty and the Beast</i>
Co-starred in the 3D film "The Smurfs," based on the 1980s animated TV series
Received a star on the Hollywood Walk of Fame (September)
Returned for "A Very Harold & Kumar 3D Christmas"
Announced as the host and producer of the 66th Annual Tony Awards; also produced alongside Ricky Kirshner and Glenn Weiss
Starred in "The Smurfs 2"
Returned to voice Steve the Monkey in "Cloudy with a Chance of Meatballs 2"