1. “How I Met Your Mother” …. Lily Aldrin (78 episodes, 2005-2009)
2. Date Movie (2006) …. Julia Jones
3. Farce of the Penguins (2006) (V) (voice) …. Hottie Penguin
4. “Veronica Mars” …. Trina Echolls (3 episodes, 2005)
5. “King of the Hill” …. Stacey Gibson (1 episode, 2004)
6. “That ’70s Show” …. Suzy Simpson (2 episodes, 2004)
7. Buffy the Vampire Slayer: The Animated Series (2004) (TV) (voice) …. Willow Rosenberg
8. Americana (2004) (TV) …. Andrea
9. American Wedding (2003) …. Michelle Flaherty
10. “Buffy the Vampire Slayer” …. Willow Rosenberg (144 episodes, 1997-2003)
11. “Angel” …. Willow Rosenberg (3 episodes, 2001-2003)
12. Buffy the Vampire Slayer (2002) (VG) (voice) …. Willow Rosenberg
13. Beyond the City Limits (2001) …. Lexi
14. American Pie 2 (2001) …. Michelle Flaherty
15. Boys and Girls (2000) …. Betty
16. “The Wild Thornberrys” …. Gerda (1 episode, 2000)
17. “100 Deeds for Eddie McDowd” …. Gigi (2 episodes, 1999-2000)
18. American Pie (1999) …. Michelle Flaherty
19. Hayley Wagner, Star (1999) (TV) …. Jenna Jakes
20. Dead Man on Campus (1998) …. Lucy
21. For My Daughter’s Honor (1996) (TV) …. Kelly
22. “Picket Fences” …. Peggy Patterson (1 episode, 1996)
23. A Case for Life (1996) (TV) …. Iris
24. The Stranger Beside Me (1995) (TV) …. Dana
25. “Touched by an Angel” …. Cassie Peters (1 episode, 1994)
26. “Almost Home” …. Samantha (2 episodes, 1993)
27. Switched at Birth (1991) (TV) …. Gina Twigg, Age 13-16
28. “Roseanne” …. Jan (1 episode, 1990)
29. “Free Spirit” …. Jessie Harper (14 episodes, 1989-1990)
30. My Stepmother Is an Alien (1988) …. Jessie Mills
31. Impure Thoughts (1986) (as Allison Hannigan) …. Patty Stubbs

Soundtrack

1. “Buffy the Vampire Slayer” (1 episode, 2001)
   - Once More, with Feeling (2001) TV episode (performer: “I’ve Got A Theory”, “Bunnies”, “If We’re Together”, “Walk Through The Fire”)

Self:

1. “Entertainment Tonight” …. Herself (1 episode, 2008)
2. “The Bonnie Hunt Show” …. Herself (1 episode, 2008)
3. “Late Night with Conan O’Brien” …. Herself (7 episodes, 1999-2008)
4. “Live with Regis and Kathie Lee” …. Herself (1 episode, 2008)
5. “The Late Late Show with Craig Ferguson” …. Herself (3 episodes, 2005-2008)
6. “CBS Cares” …. Herself (4 episodes, 2005-2008)
7. The 49th Annual Grammy Awards (2007) (TV) …. Herself
8. The 33rd Annual People’s Choice Awards (2007) (TV) …. Herself
9. “The Megan Mullally Show” …. Herself (1 episode, 2006)
10. “Last Call with Carson Daly” …. Herself (3 episodes, 2005-2006)
11. “MADtv” …. Herself – Guest (1 episode, 2006)
12. “Ellen: The Ellen DeGeneres Show” …. Herself (2 episodes, 2005-2006)
13. “I Love the 80′s 3-D” (2005) TV series …. Herself
14. “The View” …. Herself (1 episode, 2005)
15. “The 100 Most Memorable TV Moments” (2004) TV mini-series …. Herself
16. ‘Buffy’: Season 7 Overview (2004) (V) …. Herself
17. ‘Buffy’: Season 6 Overview (2004) (V) …. Herself
18. “T4″ …. Herself (1 episode, 2004)
19. “Richard & Judy” …. Herself (1 episode, 2004)
20. “Breakfast” …. Herself (1 episode, 2004)
21. “Style Star” …. Herself (1 episode, 2004)
22. Comedy Central Presents: The Commies (2003) (TV) …. Herself
23. “Talking to Animals” …. Herself (1 episode, 2003)
24. “The Tonight Show with Jay Leno” …. Herself (1 episode, 2003)
25. “Pepsi Smash” …. Host (1 episode, 2003)
26. “The Daily Show” …. Herself (1 episode, 2003)
27. 2003 MTV Movie Awards (2003) (TV) …. Herself
28. “The Late Late Show with Craig Kilborn” …. Herself (2 episodes, 2001-2003)
29. “Biography” …. Herself (1 episode, 2003)
30. The Teen Choice Awards 2002 (2002) (TV) …. Herself – Presenter
31. “VH-1 Behind the Movie” …. Herself (1 episode, 2002)
32. “Backstory” …. Herself / … (1 episode, 2002)
33. Good Times with Cast and Crew of ‘American Pie 2′ (2002) (V) …. Herself
34. “Celebrity Adventures” …. Herself (1 episode, 2001)
35. “The Big Breakfast” …. Herself (2 episodes, 2000-2001)
36. “Howard Stern” …. Herself (2 episodes, 2001)
37. 2001 MTV Movie Awards (2001) (TV) …. Herself
38. Playboy Exposed: Playboy Mansion Parties Uncensored (2001) (V) …. Herself
39. 2000 MTV Movie Awards (2000) (TV) …. Herself – Presenter
40. “TFI Friday” …. Herself (1 episode, 2000)
41. “This Morning” …. Herself (1 episode, 2000)
42. “Nyhetsmorgon” …. Herself (1 episode, 1999)
43. “Donny & Marie” …. Herself (1 episode, 1999)
44. Spotlight on Location: American Pie (1999) (TV) …. Herself
45. 1999 MTV Movie Awards (1999) (TV) …. Herself
46. MTV Presents: Videos That Don’t Suck (1998) (TV) …. Herself

Archive Footage

1. “Time Shift”
   - Parallel Worlds: A User’s Guide (2007) TV episode (uncredited) …. Willow Rosenberg
2. Sex at 24 Frames Per Second (2003) (V) …. Herself
3. ‘Angel’: Season One (2003) (V) (uncredited) …. Willow Rosenberg