1: 1. Jessica Alba made a guest appearance on NCIS. 2. Jamie Lee Curtis starred in an episode of NCIS. 3. Joe Spano played Tobias Fornell on NCIS.

2: 4. Lily Tomlin made a cameo on NCIS. 5. Chad Michael Murray guest-starred on NCIS. 6. Jeri Ryan appeared as Rebecca Chase on NCIS.

3: 7. Michael Weatherly portrayed Tony DiNozzo on NCIS. 8. Rena Sofer played Margaret Allison Hart on NCIS. 9. Maria Bello joined the cast as Jacqueline Sloane on NCIS.

4: 10. Rick Springfield guest-starred on NCIS. 11. Scottie Thompson appeared as Jeanne Benoit on NCIS. 12. Sasha Alexander starred as Caitlin Todd on NCIS.

5: 13. Brian Dietzen plays Dr. Jimmy Palmer on NCIS. 14. Mark Harmon stars as Leroy Jethro Gibbs on NCIS. 15. Cote de Pablo portrayed Ziva David on NCIS.

6: 16. Lauren Holly guest-starred as Jenny Shepard on NCIS. 17. Michael Nouri played Eli David on NCIS. 18. Dina Meyer appeared as Holly Snow on NCIS.

7: 19. Sean Murray stars as Timothy McGee on NCIS. 20. Pauley Perrette portrayed Abby Sciuto on NCIS. 21. David McCallum played Donald Mallard on NCIS.

8: 22. Emily Wickersham portrayed Eleanor Bishop on NCIS. 23. Wilmer Valderrama joined the cast as Nick Torres on NCIS. 24. Rocky Carroll stars as Leon Vance on NCIS.

9: 25. Robert Wagner guest-starred on NCIS. 26. Sarah Clarke played Tess Monroe on NCIS. 27. Muse Watson appeared as Mike Franks on NCIS.