Film

2008: Harold & Kumar Escape from Guantanamo Bay - Himself
2008: Justice League: The New Frontier - Barry Allen/The Flash
2005: The Golden Blazer - The Comic Shop Owner
2004: Harold & Kumar Go To White Castle - Himself
2002: The Mesmerist - Benhamin
2000: The Next Best Thing - David
1998: The Proposition - Roger Martin
1997: Starship Troopers - Colonel Carl Jenkins
1995: Aninal Room - Arnold Mosk
1988: Purple People Eater - Billy Johnson
1988: Clara's Hart - David Hart

Other TV

2007: Family Guy - (5.16) - Barney
2005 - 2008: How I Met Your Mother - Barney Stinson
2005: The Christmas Blessing (TV Movie) Nathan Andrews
2005: Jack & Bobby (1.17) - Preston Phelps
2005: Numb3rs (1.5) - Ethan Burdick
2005: Law & Order: Criminal Intent (4.3) - John Tagman
2003: Spider-Man - Peter Parker/Spider-Man
2003: Boomtown (1.11) - Peter Corman
2002: Justice League (1.16 | 1.17) - Ray Thompson
2002: Touched by an Angel (8.16) - Jonas
2001: Ed (2.6) - Joe Baxter
2001: Sweeney Todd: The Demon Barber of Fleet Street in Concert (TV Movie) - Tobias Rigg
2001: The Wedding Dress (TV Movie) - Travis Cleveland
2001: Son of the Beach (2.5) - Loverboy
2001: Static Shock (1.12) - Johnny Morrow/Replay
2000: Will & Grace (2.20) - Bill
1999 - 2000: Stark Raving Made - Henry McNeeley
1999: Joan of Arc (TV Movie) - The Dauphin, later King Charles VII of France
1998: The Christmas Wish (TV Movie) - Will Martin
1997: Homicide: Life on the Street (5.16) - Alan Schack
1996: The Outer Limits (2.13) - Howie Morrison
1995: Legacy of Sin: The William Coit Stroy (TV Movie) - William Coit
1995: My Antonia (TV Movie) - Jimmy Burden
1995: Not Our Son (TV MOvie) - Paul Kenneth Keller
1995: Capitol Critters (1.13) - Max
1995: The Man in the Attic (TV MOvie) - Edward Broder
1994: Snowbound: The Jim and Jennifer Stolpa Story (TV Movie) - Jim Stolpa
1993: A Family Torn Apart (TV Movie) - Brian Hannigan
1993: Mruder, She Wrote (9.19) - Tommy Remsen
1993: Quantum Leap (5.16) - Mike Hammond
1992: Roseanne (4.16) - Dr. Doogie Howser
1991: Blossom (2.9) - The 'Charming' Derek Slade
1991: Stranger in the Family (TV Movie) - Steve Thompson
1991: The Simpsons (3.4) - Himself
1990: Captain Planet and the Planeteers - Todd Andrews
1989 - 1993: Doogie Howser, M.D. - Doogie Howser
1989: Cold Sassy Tree (TV MOvie) - Will Tweedy/Narrator
1989: B.L. Stryker (1.5)
1989: Home Fires Burning (TV Movie) - Lonnie Tibbetts
1988: Too Good to Be True (TV Movie) - Danny Harland

As Himself

2008: Million Dollar Password (1.1)
2008: Jimmy Kimmel Live! (25 Apr 2008)
2008: Mad TV (13.14)
2007 - 2008: Entertainment Tonight (2 Feb 2007 | 16 Apr 2007 | 19 Jul 2007 | 6 Sep 2007 | 20 Sep 2007 | 21 Sep 2007 | 15 Oct 2007 | 5 Nov 2007 | 26 Nov 2007 | 11 Mar 2008 | 14 Mar 2008 | 18 Apr 2008 | 7 May 2008 | 9 May 2008 | 13 May 2008 | 27 May 2008)
2007: Wheel of Fortune (12 Nov 2007)
2007: 2007 Primetime Creative Arts Emmy Awards
2007: The Visible Vote '08 - A Presidential Forum
2007: The 61st Annual Tony Awards
2007: The States (1.3)
2007: The Morning Show with Mike & Juliet (1.71)
2007: Film Independent's 2007 Spirit Awards
2006 - 2008: Late Night with Conan O'Brien (27 Jun 2006 | 21 Mar 2007 | 21 Nov 2007 | 15 Feb 2008)
2006: The Megan Mully Show (1.32 | 1.50)
2006: Jeopardy! (13 Nov 2006)
2006: Square Off (1.19)
2006: Big Brother (7.23)
2006: 2006 Primetime Creative Arts Emmy Awards
2006: The 60th Annual Tony Awards
2006: The Daily Show with Jon Stewart (19 Jan 2006)
2005 - 2008: Ellen: The Ellen DeGeneres Show (7 Nov 2005 | 19 Apr 2007 | 13 Sep 2007 | 23 Apr 2008)
2005 - 2007: The Late Late Show with Craig Ferguson (2.1 | 2.133 | 3.71)
2005: The Tony Danza Show (2.18)
2005: The View (30 Sep 2005)
2005: Breakfast with the Arts (10 Apr 2005)
2005: An Interview with Neil Patrick Harris
2004 - 2008: Live with Regis (18 Aug 2004 | 23 Mar 2005 | 23 Mar 2007 | 7 Jun 2007 | 8 June 2007 | 19 Nov 2007 | 15 Feb 2008 | 21 April 2008 | 23 May 2008)
2004: Celebrity Poker Showdown (4.4 | 4.6)
2004: Last Call with Carson Daly (5 May 2004)
2003: Pyramid (5 Nov 2003 | 7 Nov 2003)
2002: Playboy: Inside the Playboy Mansion
2002: Death from Above: The Making of 'Starship Troopers'
2001: Access Granted (15 April 2001)
1999: The Martin Short Show (1.29)
1997 & 2000: The Rosie O'Donnel Show (21 Oct 1997 | 1 Feb 2000)
1994 & 2006: Late Show with David Letterman (5 Jan 1994 | 13 Oct 2006)
1993: For Our Children
1992: For Our Children: The Concert (TV Movie)
1992: This Is MST3K
1992: Time Out: The Truth About HIV, AIDS and You
1991: The Best of Disney: 50 Years of Magic
1991: The 5th Annual American Comedy Awards
1990 - 1991: The Tonight Show Starring Johnny Carson (13 Mar 1990 | 7 Nov 1990 | 18 Oct 1991)
1990: The Earth Day Special
1989: The More You Know

Film

2008: Prairie Fever - Blue
2008: Dear Me - Pipsy
2007: Splitting Hairs - Sugar Girl
2006: God's Waiting List - Trixie
2005: Short Story Time - Felicia
2004: The Mortician's Hobby - Tiffany
2004: Bring It on Again - Penelope
2004: Final Sale - Felicia
2003: Backslide - Maddie
2001: Strings
2000: Delusional

Other TV

2008: The Guild - Codex/Writer/Producer
2006: Windfall (1.7 | 1.10) - Danielle
2006: Love, Inc (1.14) - Natalie
2006: Hotel Erotica Cabo (3.1) - Molly
2005: Monk (4.5) - Mrs Hiedi Gefsky
2005: Mystery Woman: Vision of a Murder -(TV Movie) - Emily
2005: Warm Springs (TV Movie) - Eloise Hutchinson
2004: One on One (4.2) - Sarah
2004: Strong Medicine (5.1) - Jesse's Friend
2004: June (TV Movie) - June Marie Jacobs
2003: For the People (1.16) - Nicole
2002: They Shoot Divas, Don't They? (TV Movie) - Call Girl
2002: House Blend (TV Movie) - Pam
2002: Maybe It's Me (1.17) - Cookie
2001: Emeril (1.4) - Cherie

As Herself

2003: Player$ (2.11)

Commercials

2007:T-Mobile
2005:Clearasil Ultra Face Wash
2004:United States Postal Service
2004:Carb Countdown Yoghurt Drink
2003:Diet Coke
2003:Parents: The Anti-Drug
Cheetos