Prime-time viewership numbers compiled by Nielsen Media Research for May 11-17. Listings include the week’s ranking, with viewership for the week and season-to-date rankings in parentheses. An “X” in parentheses denotes a one-time-only presentation.

1. (1) “American Idol” (Wednesday), Fox, 24.67 million viewers.
2. (2) “American Idol” (Tuesday), Fox, 22.71 million viewers.
3. (3) “Dancing with the Stars,” ABC, 18.55 million viewers.
4. (15) “Grey’s Anatomy,” ABC, 16.53 million viewers.
5. (7) “The Mentalist,” CBS, 16.21 million viewers.
6. (5) “NCIS,” CBS, 16.20 million viewers.
7. (4) “CSI: Crime Scene Investigation,” CBS, 14.81 million viewers.
8. (8) “Dancing with the Stars Results,” ABC, 14.06 million viewers.
9. (9) “Desperate Housewives,” ABC, 13.96 million viewers.
10. (13) “CSI: Miami,” CBS, 13.59 million viewers.
11. (17) “Without a Trace,” CBS, 13.4 million viewers.
12. (12) “Criminal Minds,” CBS, 13.37 million viewers.
13. (11) “Two and a Half Men,” CBS, 13.11 million viewers.
14. (X) “Survivor: Tocantins Finale,” CBS, 12.94 million viewers.
15. (X) “CSI: NY” (Special), CBS, 12.77 million viewers.
16. (19) “House,” Fox, 12.74 million viewers.
17. (16) “CSI: NY,” CBS, 12.33 million viewers.
18. (17) “Survivor: Tocantins,” CBS, 12.18 million viewers.
19. (36) “Biggest Loser 7,” NBC, 11.85 million viewers.
20. (X) “Survivor: Tocantins Reunion,” CBS, 11.59 million viewers.