Weekly Ratings: 2/16 – 2/20

Monday Ratings: Chuck Spies a Series Low

8 pm/ET
House dipped a bit yet still topped the hour with 14 million total viewers. Placing second, The Bachelor (12.5 mil) courted 15 percent more viewers than a week ago. Chuck came in fourth (behind CBS sitcom repeats) with 6.75 million viewers — a 19 percent plunge from its 3-D showcase, a 600K drop from its most recent 2-D outing, and the series' lowest rating ever for a fresh eppy.

9 pm
24 gained six percent and added viewers across the hour, averaging 11.16 mil. Leading out of a Two and a Half Men rerun, Worst Week's finale managed 8.7 mil (down 13 percent). Heroes sagged a bit, to 7.74 mil.

10 pm
Opposite a warmed-over CSI: Miami, Medium (8.94 million viewers) super-sized its audience by 13 percent, while True Beauty (7.04 mil) added 220K to its last Monday outing.

Tuesday Ratings: How Badly Did Idol Mess with The Mentalist?

8 pm/ET
Let the stinging singing begin. American Idol averaged 25.1 million total viewers over its two-hour run, a 13 percent drop from last year's first big croon-off. Placing second in the hour, NCIS held steady at 18 mil. The Biggest Loser (8.9 mil) was the biggest loser of the night at Idol's hand, shedding 13 percent of its week-ago audience.

9 pm
Opposite the second hour of Idol (noooo, don't go near The Police!), The Mentalist only dipped 7 percent from last week's all-time high. In other words, barely a hair on Simon Baker's head was mussed.

10 pm
Without a Trace's yo-yo act continued, with the procedural this week slipping 16 percent, to 12.2 million viewers. SVU placed second with 9.45 mil (down 900K), yet topped the demos.

Wednesday Ratings: Lost Bounces Baaaaaaack from Last Week

8 pm/ET
American Idol cued up an audience of 24.4 million total viewers, up 5 percent from last year's first results show. CBS, which came in second for the hour, saw gains for Old Christine (7.32 mil, +260K) and Gary Unmarried (7.26 mil, +400K). This week's Lost rehash (5.57 mil) surged 17 percent to best a new Knight Rider (5.49 mil).

9 pm
Criminal Minds drew the most viewers (15 million), but Lost topped the demos. Lost bounced back from last week's "Idol-ized" setback to deliver 11.27 mil — and thus edge out Lie to Me (which dipped 78O thou, to 11.22 mil). Life inched up 440K, to 5.16 mil.

10 pm
As CSI: NY (12.35 million viewers, down 500 thou) and Law & Order (7.15 mil, down 370K) both dropped, Life on Mars saw its audience liven up by some 13 percent, hitting 5.8 mil.

Thursday Ratings: Grey's Anatomy Puts Up a Good Fight

8 pm/ET
Survivor: Tocantins inched up slightly from its premiere to win the hour with 13.67 million total viewers. Bones cinched second with 9.5 million (down 12 percent from its fresh eppy), while Ugly Betty settled for third (7.65 mil). NBC's Earl (6.72 mil) gained 420K, but Kath & Kim (5.13 mil) scared off another 350 thou.

9 pm
CSI topped the hour with 16.85 million viewers, dropping 930K. Grey's Anatomy's scalpel-vs.-scalpel and fist-vs.-fist showdowns drummed up 15.39 mil, a week-to-week increase of 310K and the series' biggest audience since Nov. 20, 2008. (Was it just me or did Addison seem a bit, um, turned on by the boys' McDonnybrook?)

10 pm
With the Grey's crossover over, Private Practice plunged 20 percent yet still edged out Eleventh Hour — 11.37 mil to 11.23 mil. (Who took my Twitter challenge and spotted Private Practice's second, non-Anya Buffy alum?) ER delivered 7.44 mil, up 190K.

Friday Ratings: Dollhouse Gets Fewer Visitors, Conan Bows Out Big

8 pm/ET
A repeat of Ghost Whisperer's season opener topped the hour with 8.35 million total viewers. Trailing both a warmed-over Wife Swap (4.09 mil) and Howie Do It (3.89 mil), Sarah Connor Chronicles came in fourth with 3.84 million viewers, up four percent from its Friday time-slot premiere.

9 pm
Dollhouse came in third behind a Flashpoint repeat (8.06 million viewers) and Supernanny (5.25 mil), dipping 10 percent from its premiere to 4.22 mil. That said, Dollhouse actually gained viewers over the hour. Friday Night Lights surged 14 percent to just under four mil.

10 pm
A Numbers repeat was No. 1 with 7.99 million viewers, followed by 20/20 (7.27 mil) and Dateline (5.57 mil).

Late Night
Conan O'Brien's final Late Night drew the talker's best numbers since Dec. 8, 2006, representing a 44 percent increase on his average for this season.